Version:            (using KDE 4.2.0)
Compiler:          gcc (GCC) 4.3.3  (is that what you want here?) 
OS:                Linux
Installed from:    Unlisted Binary Package

I have an auto-hide panel at the top of my desktop, with several widgets.  I tried dragging the Incoming Message widget off of the auto-hide panel and onto the desktop when the crash occured.

Programs that were also running, include Dolphin, Konsole, Firefox (Gran Paradiso), Okular with a PDF file, KWrite, Xchat, Korganizer Daemon, Knotes, battery monitor (widget on bottom panel), Klipper.

As I'm writing this, my cpu fan has revved up.  Must need to reboot because of the crash, although it appeared to recover well... using "top", I see that plasma and X are taking 30% and 20%, respectively, of my dual core cpu

Application: Plasma Workspace (plasma), signal SIGSEGV
[Current thread is 0 (LWP 2636)]

Thread 4 (Thread 0xa9226b90 (LWP 2637)):
#0  0xb8076424 in __kernel_vsyscall ()
#1  0xb6982c55 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/libpthread.so.0
#2  0xb69fa6a2 in QWaitCondition::wait () from /usr/lib/libQtCore.so.4
#3  0xb7af1a0a in ?? () from /usr/lib/libQtNetwork.so.4
#4  0x0923ebb0 in ?? ()
#5  0x0923ebac in ?? ()
#6  0xffffffff in ?? ()
#7  0xb6b72000 in ?? ()
#8  0xa92262f0 in ?? ()
#9  0xb808541b in _dl_fixup () from /lib/ld-linux.so.2
#10 0xb69f9910 in ?? () from /usr/lib/libQtCore.so.4
#11 0x0923eba0 in ?? ()
#12 0x00000000 in ?? ()

Thread 3 (Thread 0xa892ab90 (LWP 2648)):
#0  0xb8076424 in __kernel_vsyscall ()
#1  0xb6982c55 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/libpthread.so.0
#2  0xb69fa6a2 in QWaitCondition::wait () from /usr/lib/libQtCore.so.4
#3  0xa949380a in RenderThread::run () from /usr/lib/kde4/plasma_wallpaper_image.so
#4  0xb69f9910 in ?? () from /usr/lib/libQtCore.so.4
#5  0x08f7ee5c in ?? ()
#6  0x00000000 in ?? ()

Thread 2 (Thread 0xa714fb90 (LWP 2703)):
#0  0xb8076424 in __kernel_vsyscall ()
#1  0xb67d7ab1 in select () from /lib/libc.so.6
#2  0xb6ab7bf7 in ?? () from /usr/lib/libQtCore.so.4
#3  0x00000008 in ?? ()
#4  0xa714f278 in ?? ()
#5  0x00000000 in ?? ()

Thread 1 (Thread 0xb4909730 (LWP 2636)):
[KCrash Handler]
#6  0xb721455d in QGraphicsLinearLayout::removeItem () from /usr/lib/libQtGui.so.4
#7  0xb804c3f0 in PanelAppletOverlay::mousePressEvent () from /usr/lib/libkdeinit4_plasma.so
#8  0xb6d2fd1a in QWidget::event () from /usr/lib/libQtGui.so.4
#9  0xb6cddaec in QApplicationPrivate::notify_helper () from /usr/lib/libQtGui.so.4
#10 0xb6ce4863 in QApplication::notify () from /usr/lib/libQtGui.so.4
#11 0xb78a7f2d in KApplication::notify () from /usr/lib/libkdeui.so.5
#12 0xb6ad3f31 in QCoreApplication::notifyInternal () from /usr/lib/libQtCore.so.4
#13 0xb6ce5be3 in QApplicationPrivate::sendMouseEvent () from /usr/lib/libQtGui.so.4
#14 0xb6d42715 in ?? () from /usr/lib/libQtGui.so.4
#15 0x09b3eb08 in ?? ()
#16 0xbfb933dc in ?? ()
#17 0x09b3eb08 in ?? ()
#18 0x092de818 in ?? ()
#19 0xb7310bd0 in ?? () from /usr/lib/libQtGui.so.4
#20 0xb7310bd4 in ?? () from /usr/lib/libQtGui.so.4
#21 0xbfb9345c in ?? ()
#22 0x00000028 in ?? ()
#23 0x09a53f60 in ?? ()
#24 0x09a53000 in ?? ()
#25 0xb6779bae in mem2chunk_check () from /lib/libc.so.6
#26 0xb6d41bcd in QApplication::x11ProcessEvent () from /usr/lib/libQtGui.so.4
#27 0xb6d67172 in ?? () from /usr/lib/libQtGui.so.4
#28 0x08dbb988 in ?? ()
#29 0xbfb938bc in ?? ()
#30 0x00000000 in ?? ()