I think im having a problem here. Im not unlocking any achievements that i have completed (apart from maybe 5) the achievements im talking about are the Steam ones, not the challenges in game. Anyone else have this problem?

If you've opened the console at all by pressing ~ (right next to 1 and above Tab) then your achievements will not unlock.

That's from my experiences..
They really need to make a way to disable the console.. I'm always afraid of opening it now. >.<

Ah that would be the problem, i had to use it to get unstuck in a spot. Well that svcks then.
Will it only not get me the achievements if i used it once, or just in that session of playing? (like if i exit game and start playing again)