Hi. First off, go to My LQ, edit profile, and enter your distro in the "distro" field. In that way, you won't have to state it over and over again (unless you use more than one).
Second, I don't know what's up with gaim, but I suggest you try another yim client to see if the problem is gaim-specific (centericq and bitlbee spring to mind). Can you send messages over YIM with those? If so, you at least have a workaround. Try up- or downgrading gaim, does that fix anything? If so, there's an even better workaround (and it'll probably fix itself as FC starts distributing a version that works).