Application that crashed: plasma-desktop
Version of the application: 0.3
KDE Version: 4.3.00 (KDE 4.3.0)
Qt Version: 4.5.2
Operating System: Linux 2.6.28-14-generic x86_64
Distribution: Ubuntu 9.04

What I was doing when the application crashed:
Plasma crashes immediately after entering username/password on login. I did sudo aptitude safe-upgrade, restarted, and had the plasma crash. 

 -- Backtrace:
Application: Plasma Workspace (kdeinit4), signal: Segmentation fault
[KCrash Handler]
#5  0x00007fb1d9965c60 in strlen () from /lib/libc.so.6
#6  0x00007fb1beb8970f in PyString_FromFormatV (format=0x7fb1be31d8e0 "the sip module supports API v%d.0 to v%d.%d but the %s module requires API v%d.%d", vargs=0x7fffe54e22b0)
    at ../Objects/stringobject.c:210
#7  0x00007fb1bebe7b50 in PyErr_Format (exception=0x7fb1bef2aae0, format=0x0) at ../Python/errors.c:546
#8  0x00007fb1be3198b5 in sip_api_export_module (client=0x7fb1bd9c1e20, api_major=<value optimized out>, api_minor=<value optimized out>, mod_dict=0x0)
    at /build/buildd/sip4-qt3-4.7.9/siplib/siplib.c:914
#9  0x00007fb1bd647468 in initplasma () at sipplasmapart0.cpp:2357
#10 0x00007fb1bebf2ab6 in _PyImport_LoadDynamicModule (name=0x7fffe54e35a0 "PyKDE4.plasma", pathname=0x7fffe54e24d0 "/usr/lib/python2.6/dist-packages/PyKDE4/plasma.so", fp=<value optimized out>)
    at ../Python/importdl.c:53
#11 0x00007fb1bebf0f49 in import_submodule (mod=0x1b00210, subname=0x7fffe54e35a7 "plasma", fullname=0x7fffe54e35a0 "PyKDE4.plasma") at ../Python/import.c:2590
#12 0x00007fb1bebf11e2 in load_next (mod=0x1b00210, altmod=0x1b00210, p_name=<value optimized out>, buf=0x7fffe54e35a0 "PyKDE4.plasma", p_buflen=0x7fffe54e3598) at ../Python/import.c:2410
#13 0x00007fb1bebf1888 in import_module_level (name=0x0, globals=<value optimized out>, locals=<value optimized out>, fromlist=0x18a2490, level=<value optimized out>) at ../Python/import.c:2139
#14 0x00007fb1bebf1e3f in PyImport_ImportModuleLevel (name=0x1963914 "PyKDE4.plasma", globals=0x19a6650, locals=0x19a6650, fromlist=0x18a2490, level=-1) at ../Python/import.c:2183
#15 0x00007fb1bebd41dd in builtin___import__ (self=<value optimized out>, args=<value optimized out>, kwds=<value optimized out>) at ../Python/bltinmodule.c:48
#16 0x00007fb1beb32c48 in PyObject_Call (func=0x1878050, arg=0x1951af8, kw=0x0) at ../Objects/abstract.c:2492
#17 0x00007fb1bebd47c6 in PyEval_CallObjectWithKeywords (func=0x1878050, arg=0x1951af8, kw=0x0) at ../Python/ceval.c:3575
#18 0x00007fb1bebd86ad in PyEval_EvalFrameEx (f=0x19a7190, throwflag=<value optimized out>) at ../Python/ceval.c:2136
#19 0x00007fb1bebdb9a9 in PyEval_EvalCodeEx (co=0x195c558, globals=<value optimized out>, locals=<value optimized out>, args=0x0, argcount=0, kws=0x0, kwcount=0, defs=0x0, defcount=0, closure=0x0)
    at ../Python/ceval.c:2968
#20 0x00007fb1bebdbac2 in PyEval_EvalCode (co=0x0, globals=0x7fffe54e22b0, locals=0x28) at ../Python/ceval.c:522
#21 0x00007fb1bebee2f0 in PyImport_ExecCodeModuleEx (name=0x7fffe54e6bf0 "pyappletscript", co=0x195c558, pathname=0x7fffe54e4aa0 "/usr/share/kde4/apps/plasma_scriptengine_python/pyappletscript.pyc")
    at ../Python/import.c:680
#22 0x00007fb1bebf007c in load_source_module (name=0x7fffe54e6bf0 "pyappletscript", pathname=0x7fffe54e4aa0 "/usr/share/kde4/apps/plasma_scriptengine_python/pyappletscript.pyc", 
    fp=<value optimized out>) at ../Python/import.c:1016
#23 0x00007fb1bebf0f49 in import_submodule (mod=0x7fb1bef35e90, subname=0x7fffe54e6bf0 "pyappletscript", fullname=0x7fffe54e6bf0 "pyappletscript") at ../Python/import.c:2590
#24 0x00007fb1bebf11e2 in load_next (mod=0x7fb1bef35e90, altmod=0x7fb1bef35e90, p_name=<value optimized out>, buf=0x7fffe54e6bf0 "pyappletscript", p_buflen=0x7fffe54e6be8) at ../Python/import.c:2410
#25 0x00007fb1bebf183c in import_module_level (name=0x0, globals=<value optimized out>, locals=<value optimized out>, fromlist=0x1886d40, level=0) at ../Python/import.c:2132
#26 0x00007fb1bebf1e3f in PyImport_ImportModuleLevel (name=0x1960fdc "pyappletscript", globals=0x199f2c0, locals=0x199f2c0, fromlist=0x1886d40, level=0) at ../Python/import.c:2183
#27 0x00007fb1bebd41dd in builtin___import__ (self=<value optimized out>, args=<value optimized out>, kwds=<value optimized out>) at ../Python/bltinmodule.c:48
#28 0x00007fb1beb32c48 in PyObject_Call (func=0x1878050, arg=0x1896110, kw=0x0) at ../Objects/abstract.c:2492
#29 0x00007fb1beb3540e in PyObject_CallFunction (callable=0x1878050, format=<value optimized out>) at ../Objects/abstract.c:2524
#30 0x00007fb1bebf200c in PyImport_Import (module_name=0x1960fb8) at ../Python/import.c:2770
#31 0x00007fb1bebf21d5 in PyImport_ImportModule (name=<value optimized out>) at ../Python/import.c:2043
#32 0x00007fb1bef93e86 in ImportModule (moduleName=
      {static null = {<No data fields>}, static shared_null = {ref = {_q_value = 4614}, alloc = 0, size = 0, data = 0x60b59a, clean = 0, simpletext = 0, righttoleft = 0, asciiCache = 0, capacity = 0, reserved = 0, array = {0}}, static shared_empty = {ref = {_q_value = 83}, alloc = 0, size = 0, data = 0x7fb1dd2c985a, clean = 0, simpletext = 0, righttoleft = 0, asciiCache = 0, capacity = 0, reserved = 0, array = {0}}, d = 0x7fffe54e8050, static codecForCStrings = 0x0}) at /build/buildd/kdebindings-4.3.0/python/pykde4/kpythonpluginfactory/kpythonpluginfactory.cpp:288
#33 0x00007fb1bef961ac in KPythonPluginFactory::create (this=0x185bd60, iface=<value optimized out>, parentWidget=0x0, parent=0x1865e50, args=<value optimized out>, keyword=@0x7fffe54e8370)
    at /build/buildd/kdebindings-4.3.0/python/pykde4/kpythonpluginfactory/kpythonpluginfactory.cpp:143
#34 0x00007fb1d496e26f in ?? () from /usr/lib/libplasma.so.3
#35 0x00007fb1d496e7ee in Plasma::loadScriptEngine () from /usr/lib/libplasma.so.3
#36 0x00007fb1d4903308 in ?? () from /usr/lib/libplasma.so.3
#37 0x00007fb1d4904079 in Plasma::Applet::Applet () from /usr/lib/libplasma.so.3
#38 0x00007fb1d4904b9c in Plasma::Applet::load () from /usr/lib/libplasma.so.3
#39 0x00007fb1d49139f0 in ?? () from /usr/lib/libplasma.so.3
#40 0x00007fb1d4916929 in Plasma::Containment::restoreContents () from /usr/lib/libplasma.so.3
#41 0x00007fb1d4918e73 in Plasma::Containment::restore () from /usr/lib/libplasma.so.3
#42 0x00007fb1d491c099 in Plasma::Corona::loadLayout () from /usr/lib/libplasma.so.3
#43 0x00007fb1d491dba2 in Plasma::Corona::initializeLayout () from /usr/lib/libplasma.so.3
#44 0x00007fb1d0f2f72d in ?? () from /usr/lib/libkdeinit4_plasma-desktop.so
#45 0x00007fb1d0f2f8b8 in ?? () from /usr/lib/libkdeinit4_plasma-desktop.so
#46 0x00007fb1d0f338e5 in ?? () from /usr/lib/libkdeinit4_plasma-desktop.so
#47 0x00007fb1dcfebea2 in QMetaObject::activate () from /usr/lib/libQtCore.so.4
#48 0x00007fb1dcff114f in ?? () from /usr/lib/libQtCore.so.4
#49 0x00007fb1dcfe6263 in QObject::event () from /usr/lib/libQtCore.so.4
#50 0x00007fb1da5a1f4d in QApplicationPrivate::notify_helper () from /usr/lib/libQtGui.so.4
#51 0x00007fb1da5aa18a in QApplication::notify () from /usr/lib/libQtGui.so.4
#52 0x00007fb1db6b471b in KApplication::notify () from /usr/lib/libkdeui.so.5
#53 0x00007fb1dcfd66ac in QCoreApplication::notifyInternal () from /usr/lib/libQtCore.so.4
#54 0x00007fb1dd003516 in ?? () from /usr/lib/libQtCore.so.4
#55 0x00007fb1dcfffb2d in ?? () from /usr/lib/libQtCore.so.4
#56 0x00007fb1d903520a in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#57 0x00007fb1d90388e0 in ?? () from /usr/lib/libglib-2.0.so.0
#58 0x00007fb1d9038a7c in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#59 0x00007fb1dcfffa8f in QEventDispatcherGlib::processEvents () from /usr/lib/libQtCore.so.4
#60 0x00007fb1da63abdf in ?? () from /usr/lib/libQtGui.so.4
#61 0x00007fb1dcfd4f42 in QEventLoop::processEvents () from /usr/lib/libQtCore.so.4
#62 0x00007fb1dcfd5314 in QEventLoop::exec () from /usr/lib/libQtCore.so.4
#63 0x00007fb1dcfd75e4 in QCoreApplication::exec () from /usr/lib/libQtCore.so.4
#64 0x00007fb1d0f1a1eb in kdemain () from /usr/lib/libkdeinit4_plasma-desktop.so
#65 0x0000000000407215 in _start ()

Reported using DrKonqi