I have the same Problem with Firefox Version 2.0.0.12 in Ubuntu 7.10.
It just happend short while ago - can't say exactly when though - maybe since 7.10 because I upgraded only a while ago...
I too like my Firefox on desktop 2 and when I click on a link in a mail in evolution on desktop 1 it used to open on desktop 2.
I have the same Problem with Firefox Version 2.0.0.12 in Ubuntu 7.10.
It just happend short while ago - can't say exactly when though - maybe since 7.10 because I upgraded only a while ago...
I too like my Firefox on desktop 2 and when I click on a link in a mail in evolution on desktop 1 it used to open on desktop 2.