plasma crashed with signal 7 in KPixmapCache::Private::mmapFile()

[SmedenStaal]

Binary package hint: kdebase-workspace

I am using Kubuntu 9.04 Beta
It crashed on start up!

ProblemType: Crash
Architecture: i386
DistroRelease: Ubuntu 9.04
ExecutablePath: /usr/bin/plasma
NonfreeKernelModules: nvidia
Package: kdebase-workspace-bin 4:4.2.1a-0ubuntu12
ProcCmdline: /usr/bin/plasma
ProcEnviron:
 LANG=en_US.UTF-8
 SHELL=/bin/bash
Signal: 7
SourcePackage: kdebase-workspace
StacktraceTop:
 KPixmapCache::Private::mmapFile ()
 KPixmapCache::Private::mmapFiles ()
 KPixmapCache::Private::init () from /usr/lib/libkdeui.so.5
 KPixmapCache::discard () from /usr/lib/libkdeui.so.5
 KPixmapCache::deleteCache () from /usr/lib/libkdeui.so.5
Title: plasma crashed with signal 7 in KPixmapCache::Private::mmapFile()
Uname: Linux 2.6.28-11-generic i686
UserGroups: adm admin cdrom dialout lpadmin plugdev sambashare