firefox crashes while displacing text

[DerWurzelJan]

Binary package hint: firefox-3.0

Version of Ubuntu: Kubuntu 9.04 (Jaunty) @ KDE 4.3.2
Version of Firefox: Firefox 3.0.14 for Ubuntu - canonical - 1.0

the error occurs when I mark some text of an arbitrary homepage then press the left mousebutton while the cursor is placed beyond the marked text, then move the mouse and release the button. Now I expect that a copy of the marked text is shown at its new position and emidiately "flies" back to its original position. But instead firefox and all other applications are crashing and I have to reboot the Computer.

This does not happen with "shiretoko" version 3.5.3, wich behaves as expected. It also does not happen if I deactivate "Compositing" by pressing "Alt"-"Shift"-"F12" first.

ProblemType: Bug
Architecture: i386
DistroRelease: Ubuntu 9.04
Package: firefox 3.0.14+build2+nobinonly-0ubuntu0.9.04.1
PackageArchitecture: all
ProcEnviron:
 LANGUAGE=
 LANG=de_DE.UTF-8
 SHELL=/bin/bash
SourcePackage: firefox-3.0
Uname: Linux 2.6.28-15-generic i686