Same here. Don't quite remember what update I did last night, it was 220kb or something like that and YM was working before that update (with PR1.3). AIM, Skype, Gtalk all working fine though.

edit: just tried to delete and then add the YM account. Deleting was successfull, can't add the account now though, lol.

edit #2: there is an update in extras-devel for the protocols plugin that fixed my problems with YM. It's worth checking out but again, beware, it is extras-devel.