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 2.6.28-15-generic i686
Distribution: Linux Mint 7 Gloria - KDE Community Edition

What I was doing when the application crashed:
it happenned before after updating  KDE 4.3 all the  application in that time didn't appear even the toolbar everything except the error i opened firefox using the link mentioned on the error but the border wasn't exist  . i installed a mint again and reused my archive after install this error appeared again.

 -- Backtrace:
Application: Plasma Workspace (kdeinit4), signal: Segmentation fault
[KCrash Handler]
#6  0xa862f3b6 in ?? () from /usr/lib/kde4/plasma_applet_tasks.so
#7  0xa862b4d1 in ?? () from /usr/lib/kde4/plasma_applet_tasks.so
#8  0xa862befd in ?? () from /usr/lib/kde4/plasma_applet_tasks.so
#9  0xa862bfbb in ?? () from /usr/lib/kde4/plasma_applet_tasks.so
#10 0xa862cba2 in ?? () from /usr/lib/kde4/plasma_applet_tasks.so
#11 0xa862cd97 in ?? () from /usr/lib/kde4/plasma_applet_tasks.so
#12 0xa8639ae5 in ?? () from /usr/lib/kde4/plasma_applet_tasks.so
#13 0xa863a14c in ?? () from /usr/lib/kde4/plasma_applet_tasks.so
#14 0xb7faa1b8 in QMetaObject::activate () from /usr/lib/libQtCore.so.4
#15 0xb7faae42 in QMetaObject::activate () from /usr/lib/libQtCore.so.4
#16 0xa866bf23 in TaskManager::TaskGroup::itemAdded () from /usr/lib/libtaskmanager.so.4
#17 0xa866cb85 in TaskManager::TaskGroup::add () from /usr/lib/libtaskmanager.so.4
#18 0xa8650383 in TaskManager::AbstractGroupingStrategy::closeGroup () from /usr/lib/libtaskmanager.so.4
#19 0xa8658077 in ?? () from /usr/lib/libtaskmanager.so.4
#20 0xa8658fab in ?? () from /usr/lib/libtaskmanager.so.4
#21 0xb7faa1b8 in QMetaObject::activate () from /usr/lib/libQtCore.so.4
#22 0xb7faae42 in QMetaObject::activate () from /usr/lib/libQtCore.so.4
#23 0xa866bed3 in TaskManager::TaskGroup::itemRemoved () from /usr/lib/libtaskmanager.so.4
#24 0xa866c8fb in TaskManager::TaskGroup::remove () from /usr/lib/libtaskmanager.so.4
#25 0xa865381d in ?? () from /usr/lib/libtaskmanager.so.4
#26 0xa865517a in TaskManager::GroupManager::qt_metacall () from /usr/lib/libtaskmanager.so.4
#27 0xb7faa1b8 in QMetaObject::activate () from /usr/lib/libQtCore.so.4
#28 0xb7faae42 in QMetaObject::activate () from /usr/lib/libQtCore.so.4
#29 0xa866f973 in TaskManager::TaskManager::taskRemoved () from /usr/lib/libtaskmanager.so.4
#30 0xa867121f in TaskManager::TaskManager::windowRemoved () from /usr/lib/libtaskmanager.so.4
#31 0xa867313c in TaskManager::TaskManager::qt_metacall () from /usr/lib/libtaskmanager.so.4
#32 0xb7faa1b8 in QMetaObject::activate () from /usr/lib/libQtCore.so.4
#33 0xb7faae42 in QMetaObject::activate () from /usr/lib/libQtCore.so.4
#34 0xb76b25c3 in KWindowSystem::windowRemoved () from /usr/lib/libkdeui.so.5
#35 0xb76b4e46 in ?? () from /usr/lib/libkdeui.so.5
#36 0xb76c3ced in NETRootInfo::update () from /usr/lib/libkdeui.so.5
#37 0xb76c49ef in NETRootInfo::event () from /usr/lib/libkdeui.so.5
#38 0xb76b50dd in ?? () from /usr/lib/libkdeui.so.5
#39 0xb75658e9 in KApplication::x11EventFilter () from /usr/lib/libkdeui.so.5
#40 0xb3cd4a47 in ?? () from /usr/lib/libkdeinit4_plasma-desktop.so
#41 0xb6ab8e5e in ?? () from /usr/lib/libQtGui.so.4
#42 0xb6acb6df in QApplication::x11ProcessEvent () from /usr/lib/libQtGui.so.4
#43 0xb6af837a in ?? () from /usr/lib/libQtGui.so.4
#44 0xb6608b88 in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#45 0xb660c0eb in ?? () from /usr/lib/libglib-2.0.so.0
#46 0xb660c268 in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#47 0xb7fc02f8 in QEventDispatcherGlib::processEvents () from /usr/lib/libQtCore.so.4
#48 0xb6af7a75 in ?? () from /usr/lib/libQtGui.so.4
#49 0xb7f931fa in QEventLoop::processEvents () from /usr/lib/libQtCore.so.4
#50 0xb7f93642 in QEventLoop::exec () from /usr/lib/libQtCore.so.4
#51 0xb7f95ae9 in QCoreApplication::exec () from /usr/lib/libQtCore.so.4
#52 0xb6a55bb7 in QApplication::exec () from /usr/lib/libQtGui.so.4
#53 0xb3cbf120 in kdemain () from /usr/lib/libkdeinit4_plasma-desktop.so
#54 0x0804e27d in _start ()

Reported using DrKonqi