[AS3]hitTesting a lot of tiles

Hi guys:hugegrin:

I`m (still:emb:) working om my platformer. And i used bitmaps to do destructable terrain. Sadly bitmaps cant be bigger than 2880 X 2880:hair: So i finaly got a way to tile my level MC up in smaller bitmaps( with some help from this forum) Now doing this totally messed up my hitTesting. I was hitTesting for one bitmap. But now i have like 20.
So i thought grouping them together somehow would be the most efficient.
So i tried to add all the tiles to a movieClip:
But if i used regular hitTestPoint on the ground MC it detects hits on the boundinBox because the bitmaps are filled with pixels:(
So i tried with the Collision Detection Kit. It worked, but was way to CPU heavy(mabye i used it wrong??)
So im kinda stuck:S

Any ideas??

Edit: I figured out i should put a screenshot on the hitTest thing…just to dont leave you guys with nothing…
This is using regular hitTestPoint and having the bitmaps added to a MC: