I thought I'd throw this one out there in case I get lucky.
StarCraft 2 has a "Play as Guest" mode that allows you to play the single player campaign off-line , just without the achievements. It was working perfectly right up to the point where patch 1.03 rolled out, and now it's broken. An error message pops up saying that to play off-line, the game client needs to be authenticated (which I did) and that I need a Battle.net profile (which I have).
The funny thing is that 1.03 was supposed to FIX off-line play for a number of users. I was one of the poor sods for whom the opposite is true...
There are quite a number of threads on the official Blizzard forums about the problem, but answers are not very forthcoming. Has anyone else encountered this?