I can't log in with the demo, well actually i don't have it anymore to try =P Windows user accounts don't seem to change the problem. The message is "Invalid account name or password, check gamesas"
I tried that fix you linked to Fewmets when it came out, but it seems the only way to make that work is to change my username from DRK3 to something else. Well, thanks for pointing it out to me though, as it looks like I will have to change my username to make it work...