Bohemia Interactive has issued a patch for ArmA II.
Update 1.02 has the following fixes:
- Lowered enemy AI skills for regular and recruit difficulty levels
- Improved Micro AI tactics, attack in pairs, path limiting to avoid passing through walls
- Fixed multiplayer session NAT negotiation
- Improved game stability (various crash opportunities fixed)
- Multiple save slots supported
- Improved terrain shape beyond map borders
- Various campaign and localization fixes and improvements
- Modules (F7) support added in the Mission Editor
- Added option to disable various post-process effects (bloom, blur etc.)
There is also a download available for a dedicated server.
You can get both over on GamersHell.