Application that crashed: dolphin
Version of the application: 1.3
KDE Version: 4.3.3 (KDE 4.3.3)
Qt Version: 4.5.2
Operating System: Linux 2.6.31-15-generic x86_64
Distribution: Ubuntu 9.10

What I was doing when the application crashed:
I created a resource location file (like *.url in Windows), I was adding some tags to it via the "Change Tags" link in Dolphin. I was testing different word separators for words in the tagname and Dolphin crashed when I added the tag "Angel Investor". 
I suppose it doesn't like spaces, but I didn't knew that. It would be nice if the user had some clues about what characters s/he can use in tags.

 -- Backtrace:
Application: Dolphin (dolphin), signal: Segmentation fault
The current source language is "auto; currently c".
[KCrash Handler]
#5  0x00007f8efb862743 in QUrl::isEmpty (this=0x24da7c8) at io/qurl.cpp:3972
#6  0x00007f8efd6fcab8 in Soprano::Node::Node(QUrl const&) () from /usr/lib/libsoprano.so.4
#7  0x00007f8efd9d2cf6 in Nepomuk::ResourceData::store (this=0x2472ed0) at ../../../nepomuk/core/resourcedata.cpp:282
#8  0x00007f8efd9d3ff0 in Nepomuk::ResourceData::setProperty (this=0x2472ed0, uri=..., value=...) at ../../../nepomuk/core/resourcedata.cpp:421
#9  0x00007f8efd9d3fac in Nepomuk::ResourceData::setProperty (this=0x237a9d0, uri=..., value=...) at ../../../nepomuk/core/resourcedata.cpp:418
#10 0x00007f8efd9eb467 in Nepomuk::Resource::addIdentifier (this=0x7fff25d039e0, value=...) at ../../../nepomuk/core/resource.cpp:519
#11 0x0000000000462bb9 in NewTagDialog::createTag (parent=<value optimized out>) at ../../../../apps/dolphin/src/panels/information/newtagdialog.cpp:82
#12 0x0000000000460531 in Nepomuk::TagCloud::mousePressEvent (this=0x16a8b80, e=<value optimized out>) at ../../../../apps/dolphin/src/panels/information/tagcloud.cpp:898
#13 0x0000000000462000 in Nepomuk::TaggingPopup::mousePressEvent (this=0x16a8b80, e=0x7fff25d044b0) at ../../../../apps/dolphin/src/panels/information/taggingpopup.cpp:122
#14 0x00007f8efbd8d9a6 in QWidget::event (this=0x16a8b80, event=0x7fff25d044b0) at kernel/qwidget.cpp:7545
#15 0x00007f8efc0e92a6 in QFrame::event (this=0x16a8b80, e=0x7fff25d044b0) at widgets/qframe.cpp:559
#16 0x0000000000461e6f in Nepomuk::TaggingPopup::event (this=0x16a8b80, e=0x24da7c8) at ../../../../apps/dolphin/src/panels/information/taggingpopup.cpp:145
#17 0x00007f8efbd3eefc in QApplicationPrivate::notify_helper (this=0x122c560, receiver=0x16a8b80, e=0x7fff25d044b0) at kernel/qapplication.cpp:4056
#18 0x00007f8efbd46011 in QApplication::notify (this=<value optimized out>, receiver=0x16a8b80, e=0x7fff25d044b0) at kernel/qapplication.cpp:3758
#19 0x00007f8efd073e56 in KApplication::notify (this=0x7fff25d091f0, receiver=0x16a8b80, event=0x7fff25d044b0) at ../../kdeui/kernel/kapplication.cpp:302
#20 0x00007f8efb8abc2c in QCoreApplication::notifyInternal (this=0x7fff25d091f0, receiver=0x16a8b80, event=0x7fff25d044b0) at kernel/qcoreapplication.cpp:610
#21 0x00007f8efbd458e0 in QCoreApplication::sendSpontaneousEvent (receiver=0x16a8b80, event=0x7fff25d044b0, alienWidget=0x0, nativeWidget=0x16a8b80, buttonDown=<value optimized out>, 
    lastMouseReceiver=<value optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:216
#22 QApplicationPrivate::sendMouseEvent (receiver=0x16a8b80, event=0x7fff25d044b0, alienWidget=0x0, nativeWidget=0x16a8b80, buttonDown=<value optimized out>, lastMouseReceiver=<value optimized out>)
    at kernel/qapplication.cpp:2924
#23 0x00007f8efbdabe2e in QETWidget::translateMouseEvent (this=0x16a8b80, event=<value optimized out>) at kernel/qapplication_x11.cpp:4343
#24 0x00007f8efbdaaaa9 in QApplication::x11ProcessEvent (this=<value optimized out>, event=0x7fff25d05fe0) at kernel/qapplication_x11.cpp:3550
#25 0x00007f8efbdd3d0c in x11EventSourceDispatch (s=<value optimized out>, callback=<value optimized out>, user_data=<value optimized out>) at kernel/qguieventdispatcher_glib.cpp:146
#26 0x00007f8ef73c9bbe in g_main_context_dispatch () from /lib/libglib-2.0.so.0
#27 0x00007f8ef73cd588 in ?? () from /lib/libglib-2.0.so.0
#28 0x00007f8ef73cd6b0 in g_main_context_iteration () from /lib/libglib-2.0.so.0
#29 0x00007f8efb8d41a6 in QEventDispatcherGlib::processEvents (this=0x1200d20, flags=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:327
#30 0x00007f8efbdd34be in QGuiEventDispatcherGlib::processEvents (this=0x24da7c8, flags=<value optimized out>) at kernel/qguieventdispatcher_glib.cpp:202
#31 0x00007f8efb8aa532 in QEventLoop::processEvents (this=<value optimized out>, flags=) at kernel/qeventloop.cpp:149
#32 0x00007f8efb8aa904 in QEventLoop::exec (this=0x7fff25d06310, flags=) at kernel/qeventloop.cpp:201
#33 0x000000000046236c in Nepomuk::TaggingPopup::exec (this=0x16a8b80, pos=<value optimized out>) at ../../../../apps/dolphin/src/panels/information/taggingpopup.cpp:110
#34 0x0000000000461546 in Nepomuk::ResourceTaggingWidget::Private::showTaggingPopup (this=0x169d750, pos=...) at ../../../../apps/dolphin/src/panels/information/resourcetaggingwidget.cpp:72
#35 0x00000000004615ec in Nepomuk::ResourceTaggingWidget::Private::_k_slotShowTaggingPopup (this=0x169d750) at ../../../../apps/dolphin/src/panels/information/resourcetaggingwidget.cpp:94
#36 0x000000000046167d in Nepomuk::ResourceTaggingWidget::qt_metacall (this=0x122c220, _c=QMetaObject::InvokeMetaMethod, _id=0, _a=0x7fff25d064f0) at ./resourcetaggingwidget.moc:89
#37 0x00007f8efb8c0ddc in QMetaObject::activate (sender=0x16a4c20, from_signal_index=<value optimized out>, to_signal_index=<value optimized out>, argv=0x0) at kernel/qobject.cpp:3113
#38 0x00007f8efc0ec0b2 in QLabel::linkActivated (this=0x24da7c8, _t1=<value optimized out>) at .moc/release-shared/moc_qlabel.cpp:169
#39 0x00007f8efc0ef9fd in QLabel::qt_metacall (this=0x16a4c20, _c=QMetaObject::InvokeMetaMethod, _id=<value optimized out>, _a=0x7fff25d06670) at .moc/release-shared/moc_qlabel.cpp:101
#40 0x00007f8efb8c0ddc in QMetaObject::activate (sender=0x16a52a0, from_signal_index=<value optimized out>, to_signal_index=<value optimized out>, argv=0x0) at kernel/qobject.cpp:3113
#41 0x00007f8efbf35095 in QTextControl::linkActivated (this=0x24da7c8, _t1=<value optimized out>) at .moc/release-shared/moc_qtextcontrol_p.cpp:309
#42 0x00007f8efbf3d099 in QTextControlPrivate::activateLinkUnderCursor (this=<value optimized out>, href=) at text/qtextcontrol.cpp:2547
#43 0x00007f8efbf3dda9 in QTextControlPrivate::mouseReleaseEvent (this=0x16a52c0, button=<value optimized out>, pos=<value optimized out>) at text/qtextcontrol.cpp:1678
#44 0x00007f8efbf40f1c in QTextControl::processEvent (this=0x16a52a0, e=0x7fff25d072e0, matrix=..., contextWidget=0x16a4c20) at text/qtextcontrol.cpp:917
#45 0x00007f8efbf371ca in QTextControl::processEvent (this=0x16a52a0, e=0x7fff25d072e0, coordinateOffset=..., contextWidget=0x16a4c20) at text/qtextcontrol.cpp:866
#46 0x00007f8efc0eca2d in QLabelPrivate::sendControlEvent (this=0x16a5010, e=0x7fff25d072e0) at widgets/qlabel.cpp:1515
#47 0x00007f8efbd8d9c0 in QWidget::event (this=0x16a4c20, event=0x7fff25d072e0) at kernel/qwidget.cpp:7549
#48 0x00007f8efc0e92a6 in QFrame::event (this=0x16a4c20, e=0x7fff25d072e0) at widgets/qframe.cpp:559
#49 0x00007f8efbd3eefc in QApplicationPrivate::notify_helper (this=0x122c560, receiver=0x16a4c20, e=0x7fff25d072e0) at kernel/qapplication.cpp:4056
#50 0x00007f8efbd46011 in QApplication::notify (this=<value optimized out>, receiver=0x16a4c20, e=0x7fff25d072e0) at kernel/qapplication.cpp:3758
#51 0x00007f8efd073e56 in KApplication::notify (this=0x7fff25d091f0, receiver=0x16a4c20, event=0x7fff25d072e0) at ../../kdeui/kernel/kapplication.cpp:302
#52 0x00007f8efb8abc2c in QCoreApplication::notifyInternal (this=0x7fff25d091f0, receiver=0x16a4c20, event=0x7fff25d072e0) at kernel/qcoreapplication.cpp:610
#53 0x00007f8efbd458e0 in QCoreApplication::sendSpontaneousEvent (receiver=0x16a4c20, event=0x7fff25d072e0, alienWidget=0x16a4c20, nativeWidget=0x15d53b0, buttonDown=<value optimized out>, 
    lastMouseReceiver=<value optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:216
#54 QApplicationPrivate::sendMouseEvent (receiver=0x16a4c20, event=0x7fff25d072e0, alienWidget=0x16a4c20, nativeWidget=0x15d53b0, buttonDown=<value optimized out>, 
    lastMouseReceiver=<value optimized out>) at kernel/qapplication.cpp:2924
#55 0x00007f8efbdaba0e in QETWidget::translateMouseEvent (this=0x15d53b0, event=<value optimized out>) at kernel/qapplication_x11.cpp:4409
#56 0x00007f8efbdaaaa9 in QApplication::x11ProcessEvent (this=<value optimized out>, event=0x7fff25d08e10) at kernel/qapplication_x11.cpp:3550
#57 0x00007f8efbdd3d0c in x11EventSourceDispatch (s=<value optimized out>, callback=<value optimized out>, user_data=<value optimized out>) at kernel/qguieventdispatcher_glib.cpp:146
#58 0x00007f8ef73c9bbe in g_main_context_dispatch () from /lib/libglib-2.0.so.0
#59 0x00007f8ef73cd588 in ?? () from /lib/libglib-2.0.so.0
#60 0x00007f8ef73cd6b0 in g_main_context_iteration () from /lib/libglib-2.0.so.0
#61 0x00007f8efb8d41a6 in QEventDispatcherGlib::processEvents (this=0x1200d20, flags=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:327
#62 0x00007f8efbdd34be in QGuiEventDispatcherGlib::processEvents (this=0x24da7c8, flags=<value optimized out>) at kernel/qguieventdispatcher_glib.cpp:202
#63 0x00007f8efb8aa532 in QEventLoop::processEvents (this=<value optimized out>, flags=) at kernel/qeventloop.cpp:149
#64 0x00007f8efb8aa904 in QEventLoop::exec (this=0x7fff25d09140, flags=) at kernel/qeventloop.cpp:201
#65 0x00007f8efb8acab9 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:888
#66 0x00000000004394e5 in main (argc=<value optimized out>, argv=<value optimized out>) at ../../../../apps/dolphin/src/main.cpp:94

Reported using DrKonqi