Can't take screenshots with Steam, what gives?

[The Cheesecake Enigma]

As the title suggests. The game is being recognized by Steam as me currently playing it, Raptr and Xfire are both picking it up when i play it, but i can't take screenshots with Steam, or even access Steam in-game when playing.

Is there anyway to fix this?

[Novocaine]

I get that too. I just print screen and paste it into pbrush.