I couldn't login with Chromium web browser, the error was:
An Error Has Occurred!
You were unable to login. Please check your cookie settings.
It's Chromium 17.0.963.83 (Developer Build 127885 Linux) Debian wheezy/sid with default settings + AdBlock Plus 1.2
There was no problem with Iceweasel.
Sorry, but that really doesn't help me at all; if I don't know what the exact problem is, I can't fix it. Have you tried completely clearing your cookies and cache and trying again? Unfortunately you're using relatively a relatively obscure browser and OS, so SMF isn't really guaranteed to work for you.
It looks like the problem is specific to my version, consider this solved.