Segfaulting (regarding flash)

Binary package hint: firefox-3.0

When loading a page containing a flash applet, Firefox will often generate a segfault showing the following error message in the console:

--start quote--
about:blank is either a broken URL or Swfdec can't parse it
Segmentation fault
--end quote--

As the word Swfdec appears in the error message, I can only deduce that there might be something wrong with the integration of the flash plugin ("Shockwave Flask 9.0 r999"). I also tried installing the FlashBlock extension and the errors didn't go away.

The error only occurs when I (re)load a certain page containing a flash applet (like http://www.youtube.com/). The error is not always reproducible, at least on my system, but it seems that it happens more than 50% of the time. Sometimes one the following error occurs instead:

--start quote--
about:blank is either a broken URL or Swfdec can't parse it

(firefox:5480): GLib-GObject-CRITICAL **: g_object_unref: assertion `G_IS_OBJECT (object)' failed
unhandled event 19
--end quote--

--start quote--
about:blank is either a broken URL or Swfdec can't parse it

(firefox:5416): GLib-GObject-CRITICAL **: g_object_unref: assertion `G_IS_OBJECT (object)' failed
Loading stream: http://s288.photobucket.com/include/swf/uploader/flash9/PBUpload.swf?v=19.0.31
unhandled event 9
unhandled event 10
unhandled event 9
unhandled event 10
--start quote--

For the times when the browser doesn't crash, when I click on the flash applet to activate it, the CPU usage booms to 100% (dual core) and the browser freezes.

ProblemType: Bug
Architecture: i386
DistroRelease: Ubuntu 8.10
NonfreeKernelModules: nvidia
Package: firefox-3.0 3.0.7+nobinonly-0ubuntu0.8.10.1
ProcEnviron:
 PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: firefox-3.0
Uname: Linux 2.6.27-11-generic i686