Version:            (using Devel)
Compiler:          gcc 4.3.0 
OS:                Linux
Installed from:    Compiled sources

Guys, I don't know if this is your bug or if I just found a bug in Qt.

I have Qt 4.4.3 from qt-copy.

I have a POP inbox and an IMAP inbox. I selected my POP inbox folder, where there was reportedly 1 new unread message, and I used the little icon on top-right to filter by status, selecting 'Unread' status. I got the following segfault:

Application: KMail (kmail), signal SIGSEGV
[Current thread is 0 (LWP 6067)]

Thread 2 (Thread 0xb0f8db90 (LWP 6159)):
#0  0xb7fbe410 in __kernel_vsyscall ()
#1  0xb4ce8881 in select () from /lib/tls/i686/cmov/libc.so.6
#2  0xb587ca90 in ?? () from /home/gaston/prefix/lib/libQtCore.so.4
#3  0xb57bdbf0 in ?? () from /home/gaston/prefix/lib/libQtCore.so.4
#4  0xb60d74fb in start_thread () from /lib/tls/i686/cmov/libpthread.so.0
#5  0xb4cefe5e in clone () from /lib/tls/i686/cmov/libc.so.6

Thread 1 (Thread 0xb427b6c0 (LWP 6067)):
[KCrash Handler]
#6  0xb5149b69 in QPainter::worldMatrixEnabled () from /home/gaston/prefix/lib/libQtGui.so.4
#7  0xb50ae134 in QWidgetPrivate::paintSiblingsRecursive () from /home/gaston/prefix/lib/libQtGui.so.4
#8  0xb50ad637 in QWidgetPrivate::drawWidget () from /home/gaston/prefix/lib/libQtGui.so.4
#9  0xb50ae134 in QWidgetPrivate::paintSiblingsRecursive () from /home/gaston/prefix/lib/libQtGui.so.4
#10 0xb50ad637 in QWidgetPrivate::drawWidget () from /home/gaston/prefix/lib/libQtGui.so.4
#11 0xb50ae134 in QWidgetPrivate::paintSiblingsRecursive () from /home/gaston/prefix/lib/libQtGui.so.4
#12 0xb50ad637 in QWidgetPrivate::drawWidget () from /home/gaston/prefix/lib/libQtGui.so.4
#13 0xb50ae134 in QWidgetPrivate::paintSiblingsRecursive () from /home/gaston/prefix/lib/libQtGui.so.4
#14 0xb50ad637 in QWidgetPrivate::drawWidget () from /home/gaston/prefix/lib/libQtGui.so.4
#15 0xb50ae134 in QWidgetPrivate::paintSiblingsRecursive () from /home/gaston/prefix/lib/libQtGui.so.4
#16 0xb50ad637 in QWidgetPrivate::drawWidget () from /home/gaston/prefix/lib/libQtGui.so.4
#17 0xb50ae134 in QWidgetPrivate::paintSiblingsRecursive () from /home/gaston/prefix/lib/libQtGui.so.4
#18 0xb50ad637 in QWidgetPrivate::drawWidget () from /home/gaston/prefix/lib/libQtGui.so.4
#19 0xb50ae134 in QWidgetPrivate::paintSiblingsRecursive () from /home/gaston/prefix/lib/libQtGui.so.4
#20 0xb50ad637 in QWidgetPrivate::drawWidget () from /home/gaston/prefix/lib/libQtGui.so.4
#21 0xb50ae134 in QWidgetPrivate::paintSiblingsRecursive () from /home/gaston/prefix/lib/libQtGui.so.4
#22 0xb50ad637 in QWidgetPrivate::drawWidget () from /home/gaston/prefix/lib/libQtGui.so.4
#23 0xb51fd29c in ?? () from /home/gaston/prefix/lib/libQtGui.so.4
#24 0xb51fd742 in ?? () from /home/gaston/prefix/lib/libQtGui.so.4
#25 0xb50b11bf in QWidget::event () from /home/gaston/prefix/lib/libQtGui.so.4
#26 0xb53b6367 in QMainWindow::event () from /home/gaston/prefix/lib/libQtGui.so.4
#27 0xb7ee9c37 in KMainWindow::event (this=0xbf9c22d0, ev=0x90f0dc8) at /home/gaston/cuisine/trunk/kdelibs/kdeui/widgets/kmainwindow.cpp:1081
#28 0xb7f2eb1c in KXmlGuiWindow::event (this=0x8264b50, ev=0x90f0dc8) at /home/gaston/cuisine/trunk/kdelibs/kdeui/xmlgui/kxmlguiwindow.cpp:131
#29 0xb505e63c in QApplicationPrivate::notify_helper () from /home/gaston/prefix/lib/libQtGui.so.4
#30 0xb50657ea in QApplication::notify () from /home/gaston/prefix/lib/libQtGui.so.4
#31 0xb7e003bd in KApplication::notify (this=0xbf9c2c18, receiver=0x8264b50, event=0x90f0dc8) at /home/gaston/cuisine/trunk/kdelibs/kdeui/kernel/kapplication.cpp:307
#32 0xb58991f1 in QCoreApplication::notifyInternal () from /home/gaston/prefix/lib/libQtCore.so.4
#33 0xb5899b43 in QCoreApplicationPrivate::sendPostedEvents () from /home/gaston/prefix/lib/libQtCore.so.4
#34 0xb5899cdd in QCoreApplication::sendPostedEvents () from /home/gaston/prefix/lib/libQtCore.so.4
#35 0xb58bfd4f in ?? () from /home/gaston/prefix/lib/libQtCore.so.4
#36 0xb4870cc6 in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#37 0xb4874083 in ?? () from /usr/lib/libglib-2.0.so.0
#38 0xb487463e in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#39 0xb58bf9a8 in QEventDispatcherGlib::processEvents () from /home/gaston/prefix/lib/libQtCore.so.4
#40 0xb50e92f5 in ?? () from /home/gaston/prefix/lib/libQtGui.so.4
#41 0xb589797a in QEventLoop::processEvents () from /home/gaston/prefix/lib/libQtCore.so.4
#42 0xb5897b3a in QEventLoop::exec () from /home/gaston/prefix/lib/libQtCore.so.4
#43 0xb5899d9d in QCoreApplication::exec () from /home/gaston/prefix/lib/libQtCore.so.4
#44 0xb505e4b7 in QApplication::exec () from /home/gaston/prefix/lib/libQtGui.so.4
#45 0x0804a980 in main (argc=-1251469768, argv=0x80000000) at /home/gaston/cuisine/trunk/kdepim/kmail/main.cpp:146