First of all, I'm totally agree with your opinion about 'B.I.' brother.
Anyway I tried several experiments and figured out little crappy workaround.
In my case, I set ARMA2OA.exe file XP compatibility mode(I'm Win7 64bit user) and in the game, when you click menu like 'Single Play', 'Campaign' etc, etc...each time. CLICK SLOWLY. This is important 'CLICK SLOWLY' about 3~5 seconds each time.
Yes, I know this workaround really funny like 286 dos game.
But It didn't crash anymore. (even in the long game session)
I played over about 8 hours without CTD...
and I noticed yesterday the patch 1.52 out recently, So I installed the patch 1.52. It doesn't crash anymore even if I don't do that crappy workaround. (including setting up XP comp. mode)
Good luck man.
FYI, my system
i5-430
ATI HD5650
DDR3 2GB RAM
Some Realtek Sound System