Steam users who snagged Batman: Arkham Asylum during Valve's Summer Sale have been unable to activate their purchases and play the game.
A good many users attempting to redeem their serial keys are being met with a "not found in database" error. If you haven't encountered this issue, consider yourself lucky, because a lot of folks have reported the problem since mid-July. A thread on the official forums shows that the issue still hasn't been resolved.
The most likely suspect in all this appears to be Arkham Asylum's DRM service, SecuROM, which brings up a new window when players launch the game. Recent keys are being rejected, according to user complaints.
Some Steam members have attempted to contact publisher Warner Bros. Interactive Entertainment in order to resolve the matter, but WBIE is still "researching the issue."