Portal 2 Patch 7 October 2011

The update will be applied automatically when your Steam client is restarted
Valve has issued a new patch for Portal 2, upgrading this sequel developed for PC, Mac, Xbox 360 and PS3. This update fixes exploits where cheats could go undetected in Challenge Mode, and fixes a rare case where a phantom laser would be stuck emitting from a redirection cube. Also, modifying gravity is now marked as a cheat.