Thanks for the report. Unfortunately, I'm unable to reproduce on 4.1 and SVN trunk rev. 840918: I opened on all messages by clicking, but got no crash.

Is this 100% reproducible for you? Sometimes you can get a backtrace with gdb:
1. enter 'gdb konqueror' in a shell
2. enter 'run' at gdb prompt
3. make Konqueror crash
4. enter 'bt' at gdb prompt

I could reproduce the crash on KDE 4.1.0 on Ubuntu Hardy x86. It took my about 20 clicks. But I tried again, and the crash didn't happen then, even when clicking 100 times or so.

Backtrace for the crash:

Application: Konqueror (konqueror), signal SIGSEGV
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
[Thread debugging using libthread_db enabled]
[New Thread 0xb60ca940 (LWP 13972)]
[KCrash handler]
#6  QWidget::mapToParent (this=0x9b7dbb0, pos=@0xbfb61ee0)
    at ../../include/QtCore/../../src/corelib/tools/qpoint.h:155
#7  0xb6a00373 in QWidget::mapTo (this=0x9b7dbb0, parent=0x9303a28, 
    pos=@0xbfb61f38) at kernel/qwidget.cpp:3493
#8  0xb6b6df6e in QWidgetBackingStore::cleanRegion (this=0x8b763d8, 
    rgn=@0xbfb61fa8, widget=0x9b7dbb0, recursiveCopyToScreen=true)
    at painting/qbackingstore.cpp:1054
#9  0xb6b6e5e7 in qt_syncBackingStore (widget=0x9b7dbb0)
    at painting/qbackingstore.cpp:319
#10 0xb6a1216f in QWidget::event (this=0x9b7dbb0, event=0xbfb62108)
    at kernel/qwidget.cpp:7209
#11 0xb42768e4 in KHTMLBackingStoreHackWidget::publicEvent (this=0x9b7dbb0, 
    e=0xbfb62108) at /build/buildd/kde4libs-4.1.0/khtml/khtmlview.cpp:2078
#12 0xb426807f in KHTMLView::eventFilter (this=0xa498ad8, o=0x9b7dbb0, 
    e=0x9cd3fe8) at /build/buildd/kde4libs-4.1.0/khtml/khtmlview.cpp:2221
#13 0xb74cea21 in QCoreApplicationPrivate::sendThroughObjectEventFilters (
    this=0x805ccd8, receiver=0x9b7dbb0, event=0x9cd3fe8)
    at kernel/qcoreapplication.cpp:694
#14 0xb69babe3 in QApplicationPrivate::notify_helper (this=0x805ccd8, 
    receiver=0x9b7dbb0, e=0x9cd3fe8) at kernel/qapplication.cpp:3768
#15 0xb69bf888 in QApplication::notify (this=0xbfb6295c, receiver=0x9b7dbb0, 
    e=0x9cd3fe8) at kernel/qapplication.cpp:3739
#16 0xb794bef3 in KApplication::notify (this=0xbfb6295c, receiver=0x9b7dbb0, 
    event=0x9cd3fe8)
    at /build/buildd/kde4libs-4.1.0/kdeui/kernel/kapplication.cpp:311
#17 0xb74ce6a9 in QCoreApplication::notifyInternal (this=0xbfb6295c, 
    receiver=0x9b7dbb0, event=0x9cd3fe8) at kernel/qcoreapplication.cpp:587
#18 0xb74cfa59 in QCoreApplicationPrivate::sendPostedEvents (receiver=0x0, 
    event_type=0, data=0x804b6b0)
    at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:215
#19 0xb74cfc7d in QCoreApplication::sendPostedEvents (receiver=0x0, 
    event_type=0) at kernel/qcoreapplication.cpp:1091
#20 0xb74f9bcf in postEventSourceDispatch (s=0x805ed90)
    at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:220
#21 0xb643cdd6 in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#22 0xb6440193 in ?? () from /usr/lib/libglib-2.0.so.0
#23 0xb644074e in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#24 0xb74f9f98 in QEventDispatcherGlib::processEvents (this=0x805a4f0, 
    flags=@0xbfb62678) at kernel/qeventdispatcher_glib.cpp:325
#25 0xb6a4e195 in QGuiEventDispatcherGlib::processEvents (this=0x805a4f0, 
    flags=@0xbfb626a8) at kernel/qguieventdispatcher_glib.cpp:204
#26 0xb74cd92d in QEventLoop::processEvents (this=0xbfb62720, 
    flags=@0xbfb626e4) at kernel/qeventloop.cpp:149
#27 0xb74cdabd in QEventLoop::exec (this=0xbfb62720, flags=@0xbfb62728)
    at kernel/qeventloop.cpp:200
#28 0xb74cfd3d in QCoreApplication::exec () at kernel/qcoreapplication.cpp:845
#29 0xb69ba567 in QApplication::exec () at kernel/qapplication.cpp:3304
#30 0xb7f7f6fd in kdemain () from /usr/lib/kde4/lib/libkdeinit4_konqueror.so
#31 0x08048582 in _start ()
#0  0xb7f99410 in __kernel_vsyscall ()

Sorry, I can't crash it.

With a news konqueror, no more problem....

It just crashed two times here while browsing this archive: http://markmail.org/message/f2bifpfgwxkzn2kf#query:Q_GLOBAL_STATIC+page:1+mid:4dm3c3wc3eknb53q+state:results

Konqueror 4.1.1, debian packages.
Backtrace:

Application: Konqueror (konqueror), signal SIGSEGV
[Thread debugging using libthread_db enabled]
[New Thread 0x7fff1d411780 (LWP 14322)]
[KCrash handler]
#5  0x00007fff1a656414 in QWidget::mapToParent (this=0x35f8dc0, 
    pos=@0x7fff25549a60) at kernel/qwidget.cpp:3555
#6  0x00007fff1a65646b in QWidget::mapTo (this=<value optimized out>, 
    parent=0x242a290, pos=@0x7fff25549b20) at kernel/qwidget.cpp:3511
#7  0x00007fff1a7bd321 in QWidgetBackingStore::cleanRegion (this=0x23950f0, 
    rgn=@0x3b452e0, widget=0x35f8dc0, recursiveCopyToScreen=true)
    at painting/qbackingstore.cpp:1052
#8  0x00007fff1a7bdf97 in qt_syncBackingStore (widget=0x35f8dc0)
    at painting/qbackingstore.cpp:319
#9  0x00007fff1a666335 in QWidget::event (this=0x35f8dc0, 
    event=0x7fff25549de0) at kernel/qwidget.cpp:7303
#10 0x00007fff0e0b352b in KHTMLView::eventFilter (this=0x2f7b010, 
    o=0x35f8dc0, e=<value optimized out>)
    at /tmp/buildd/kde4libs-4.1.1/khtml/khtmlview.cpp:2071
#11 0x00007fff19ef43f8 in QCoreApplicationPrivate::sendThroughObjectEventFilters (this=<value optimized out>, receiver=0x35f8dc0, event=0x3180d90)
    at kernel/qcoreapplication.cpp:698
#12 0x00007fff1a6143ec in QApplicationPrivate::notify_helper (this=0x238aa70, 
    receiver=0x35f8dc0, e=0x3180d90) at kernel/qapplication.cpp:3796
#13 0x00007fff1a61c17a in QApplication::notify (this=0x7fff2554a810, 
    receiver=0x35f8dc0, e=0x3180d90) at kernel/qapplication.cpp:3765
#14 0x00007fff1bffcfab in KApplication::notify (this=0x7fff2554a810, 
    receiver=0x35f8dc0, event=0x3180d90)
    at /tmp/buildd/kde4libs-4.1.1/kdeui/kernel/kapplication.cpp:311
#15 0x00007fff19ef511f in QCoreApplication::notifyInternal (
    this=0x7fff2554a810, receiver=0x35f8dc0, event=0x3180d90)
    at kernel/qcoreapplication.cpp:591
#16 0x00007fff19ef5dba in QCoreApplicationPrivate::sendPostedEvents (
    receiver=0x0, event_type=0, data=0x23752d0)
    at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:215
#17 0x00007fff19f1d7d3 in postEventSourceDispatch (s=<value optimized out>)
    at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:220
#18 0x00007fff16a4b892 in IA__g_main_context_dispatch (context=0x238caa0)
    at /build/buildd/glib2.0-2.16.5/glib/gmain.c:2012
#19 0x00007fff16a4f01d in g_main_context_iterate (context=0x238caa0, block=1, 
    dispatch=1, self=<value optimized out>)
    at /build/buildd/glib2.0-2.16.5/glib/gmain.c:2645
#20 0x00007fff16a4f1db in IA__g_main_context_iteration (context=0x238caa0, 
    may_block=1) at /build/buildd/glib2.0-2.16.5/glib/gmain.c:2708
#21 0x00007fff19f1d45f in QEventDispatcherGlib::processEvents (
    this=0x238a760, flags=<value optimized out>)
    at kernel/qeventdispatcher_glib.cpp:325
#22 0x00007fff1a6a586f in QGuiEventDispatcherGlib::processEvents (
    this=0x35f8dc0, flags=<value optimized out>)
    at kernel/qguieventdispatcher_glib.cpp:204
#23 0x00007fff19ef3a42 in QEventLoop::processEvents (
    this=<value optimized out>, flags={i = 626304336})
    at kernel/qeventloop.cpp:149
#24 0x00007fff19ef3bcd in QEventLoop::exec (this=0x7fff2554a590, flags=
      {i = 626304416}) at kernel/qeventloop.cpp:200
#25 0x00007fff19ef607d in QCoreApplication::exec ()
    at kernel/qcoreapplication.cpp:849
#26 0x00007fff1d104b71 in kdemain (argc=<value optimized out>, 
    argv=<value optimized out>)
    at /tmp/buildd/kdebase-4.1.1/apps/konqueror/src/konqmain.cpp:227
#27 0x00007fff1cd041a6 in __libc_start_main () from /lib/libc.so.6
#28 0x0000000000400629 in _start ()
#0  0x00007fff1cd840e1 in nanosleep () from /lib/libc.so.6

*** This bug has been marked as a duplicate of bug 171170 ***