I think this predates Leopard
I am reasonably sure that Tiger had the same issue, though I had not realised it was FileVault related (it did start happening when I got my first macbook I think, which had Tiger, and was the first time I used FV - I'd assumed it was the macbook/intel machine not FV causing it but FV sounds more plausible). It seems to affect all sorts of 'what should be the default applcation things - web browser, IM client, but also iScrobbler asks me if it should be the default last.fm radio player each time I log in. It's annoying, for sure.
(Splendidly stupid comment from the "just use safari person".)
--tim


