It seems that there is an incompatibility between Thunderbird 3.0.5 and libmoon0 2.2-3.2-x86_64.
On thunderbird run i got a error like:
Attempting to load the system libmoon
/usr/bin/thunderbird: line 130: 9564 Segmentation fault $MOZ_PROGRAM "$@"
After removal of libmoon everything is ok with thunderbird.
System: openSUSE 11.3 - 2.6.34-12-desktop - x64
Hmm, interesting. Does 11.3 come with those packages? I see libmoon0 is for moonlight. I don’t have it installed on 11.2. What does it do for the 11.3?
Also I’m using TB 3.1 from the Mozilla repo due to wanting to run lightning and gdata.
Anyway if both packages are off the shelf, yes, file a report.
Moonlight is the Linux port for Microsoft’s Silverlight.
I guess I’ve never bothered with sites that need Silverlight then. 
It hasn’t been as widely used as Flash, but some popular sites have switched to it (Netflix, March Madness). Most people can probably do without it, but I’m not going to miss my hoops!
Thanks for suggestion.
I have filled, now, a bug report.