I'm trying to use the MOAB mod, but it doesn't work without Extended Event Handlers, That needs CBA to work.
Well I got A2CO, so, I only installed CBA, not CBA_OA or cba_a2, I use Arma II launcher, And it works for all my addons, except this one. When I launch the game, it says that Extended event handlers need CAWeapons3, I Saw in a thread that it was CBA, but even with CBA installed it says I don't have it.
Ingame, it says that I need XEH version 3.0.6.
you probably know this error. could you help me?
PLZ
=)

What is MOAB mod?
Always provide a link when you experience issues with a certain addon.

http://forums.bistudio.com/showthread.php?t=100972
Also, you can find it in here.
Downloads>Arma II>Addons>Weapons>GBU-43 MOAB

This is not the problem, the bomb is appearing in the game, but I can't load it.
My problem is with the annoying "XEH needs CBWeapons3" error message when staring up arma

Could you help me?

Sorry, I really have no idea. Maybe its having issues with new versions of CBA or something.
Maybe its better to ask in the CBA thread which you can find here.
I hope they can help.

Only thing you should double check, are you really running CO? Maybe you did not activate both games and are in fact only running OA, or maybe only A2.
You can easily check this when you open the editor, the A2 and OA islands should be all there.