Firefox 2 "Send Link..." Doesn't

[Khoa Ton]

I'm not sure if this is an FC5 or Firefox issue, but I've
set my email application in Gnome via:
"System"->"Preferences"->"More Preferences"->"Preferred Applications"
to Thunderbird.

However, using "File"->"Send Link..." in Firefox 2.0, nothing
comes up.

Can anyone give me a pointer as to where to find any error messages
to debug this problem?

Thanks,
Khoa Ton