Application: krdc (4.6.2 (4.6.2))
KDE Platform Version: 4.6.2 (4.6.2)
Qt Version: 4.7.2
Operating System: Linux 2.6.38-11-generic x86_64
Distribution: Ubuntu 11.04

-- Information about the crash:
Crashes quite randomly. I have the impression that it crashes more frequently when using CTRL keys, though.
Using kdrc from ubuntu 11.04 repository, the remote desktop is Xvnc coming with ubuntu 10.04/gnome.

The crash can be reproduced some of the time.

-- Backtrace:
Application: KRDC (krdc), signal: Segmentation fault
[Current thread is 1 (Thread 0x7f9060174780 (LWP 3398))]

Thread 3 (Thread 0x7f904cb93700 (LWP 3399)):
#0  __libc_enable_asynccancel () at ../nptl/sysdeps/unix/sysv/linux/x86_64/cancellation.S:66
#1  0x00007f905ce00ee8 in __poll (fds=<value optimized out>, nfds=<value optimized out>, timeout=<value optimized out>) at ../sysdeps/unix/sysv/linux/poll.c:85
#2  0x00007f9059844104 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007f90598449f2 in g_main_loop_run () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#4  0x00007f9051871c44 in ?? () from /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0
#5  0x00007f905986b3e4 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#6  0x00007f9059d0fd8c in start_thread (arg=0x7f904cb93700) at pthread_create.c:304
#7  0x00007f905ce0e04d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#8  0x0000000000000000 in ?? ()

Thread 2 (Thread 0x7f903f692700 (LWP 3401)):
[KCrash Handler]
#6  0x00007f903ffeece8 in vtable for VncView () from /usr/lib/kde4/krdc_vncplugin.so
#7  0x00007f903fde66ad in VncClientThread::run (this=0x2a4be00) at ../../../krdc/vnc/vncclientthread.cpp:397
#8  0x00007f905d436175 in QThreadPrivate::start (arg=0x2a4be00) at thread/qthread_unix.cpp:320
#9  0x00007f9059d0fd8c in start_thread (arg=0x7f903f692700) at pthread_create.c:304
#10 0x00007f905ce0e04d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#11 0x0000000000000000 in ?? ()

Thread 1 (Thread 0x7f9060174780 (LWP 3398)):
#0  0x00007f905ce00f03 in __poll (fds=<value optimized out>, nfds=<value optimized out>, timeout=<value optimized out>) at ../sysdeps/unix/sysv/linux/poll.c:87
#1  0x00007f9057149512 in ?? () from /usr/lib/x86_64-linux-gnu/libxcb.so.1
#2  0x00007f905714ab3f in xcb_wait_for_reply () from /usr/lib/x86_64-linux-gnu/libxcb.so.1
#3  0x00007f905bd1c8ad in _XReply () from /usr/lib/x86_64-linux-gnu/libX11.so.6
#4  0x00007f905bd19b3d in XTranslateCoordinates () from /usr/lib/x86_64-linux-gnu/libX11.so.6
#5  0x00007f905df73aee in QWidget::mapFromGlobal (this=<value optimized out>, pos=<value optimized out>) at kernel/qwidget_x11.cpp:1336
#6  0x00007f905dee1e43 in QApplication::notify (this=<value optimized out>, receiver=0x2a4bda0, e=0x7fff8ebc0a60) at kernel/qapplication.cpp:4043
#7  0x00007f905ebff866 in KApplication::notify (this=0x7fff8ebc1780, receiver=0x2a4bda0, event=0x7fff8ebc0a60) at ../../kdeui/kernel/kapplication.cpp:311
#8  0x00007f905d51d49c in QCoreApplication::notifyInternal (this=0x7fff8ebc1780, receiver=0x2a4bda0, event=0x7fff8ebc0a60) at kernel/qcoreapplication.cpp:731
#9  0x00007f905dedda1d in sendEvent (receiver=0x2a4bda0, event=0x7fff8ebc0a60, alienWidget=0x0, nativeWidget=0x2a4bda0, buttonDown=0x7f905e9c0218, lastMouseReceiver=..., spontaneous=true) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:215
#10 QApplicationPrivate::sendMouseEvent (receiver=0x2a4bda0, event=0x7fff8ebc0a60, alienWidget=0x0, nativeWidget=0x2a4bda0, buttonDown=0x7f905e9c0218, lastMouseReceiver=..., spontaneous=true) at kernel/qapplication.cpp:3122
#11 0x00007f905df5f190 in QETWidget::translateMouseEvent (this=0x2a4bda0, event=<value optimized out>) at kernel/qapplication_x11.cpp:4558
#12 0x00007f905df5dab7 in QApplication::x11ProcessEvent (this=0x7fff8ebc1780, event=0x7fff8ebc13b0) at kernel/qapplication_x11.cpp:3680
#13 0x00007f905df86842 in x11EventSourceDispatch (s=0x2610a50, callback=0, user_data=0x0) at kernel/qguieventdispatcher_glib.cpp:146
#14 0x00007f9059843bcd in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#15 0x00007f90598443a8 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#16 0x00007f9059844639 in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#17 0x00007f905d5483ef in QEventDispatcherGlib::processEvents (this=0x25c2340, flags=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:422
#18 0x00007f905df864de in QGuiEventDispatcherGlib::processEvents (this=<value optimized out>, flags=<value optimized out>) at kernel/qguieventdispatcher_glib.cpp:204
#19 0x00007f905d51c882 in QEventLoop::processEvents (this=<value optimized out>, flags=...) at kernel/qeventloop.cpp:149
#20 0x00007f905d51cabc in QEventLoop::exec (this=0x7fff8ebc16b0, flags=...) at kernel/qeventloop.cpp:201
#21 0x00007f905d520ecb in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1008
#22 0x000000000042ab48 in main (argc=<value optimized out>, argv=<value optimized out>) at ../../krdc/main.cpp:104

Reported using DrKonqi