[CentOS] Lots of core files from 'gst-thumbnail'

I presently have 17 core.* files in my home directory, all dropped by
'gst-thumbnail'.  GDB backtraces are predictably useless, indicating
only that the crash came indirectly from libgsttypefindfunctions.so. 
I don't find anything about this in the CentOS bug tracker.  Has
anyone else seen a similar problem?

Running "strings" on the core files finds that they all mention either
    file:///home/schaefer/.mozilla/schaefer/tq3v7zkg.slt/history.dat
or
    file:///home/schaefer/.mozilla/firefox/xsml50fe.default/history.dat

And indeed I was browsing those directories (doing some manual import
of old mozilla data into my new firefox config) at the time stamped on
all the core files.

schaefer[513] rpm -qf =gst-thumbnail
nautilus-media-0.8.1-3
schaefer[514] rpm -qf /usr/lib/gstreamer-0.8/libgsttypefindfunctions.so
gstreamer-plugins-0.8.5-1.EL.0