Performance optimization

Hi, everybody!

I have a strange behaviour of my app performance:

when I go through the menu first time it looks a bit slowly, the next time after - fine. Then, when I go to level, the same with destroing the object, but the next one goes fine.

What I have observed is he in the second case, there is a jump of +10 draw calls then the destroing takes place..

Basically, it would be cool if anybody could give an advice on how to optimise the performance. What I an using is:

System.GC.Collect();

Resources.UnloadUnusedAssets();

System.GC.WaitForPendingFinalizers();

I have 30 drawcalls and even though my FPS is 20, not higher((( My that be because of my device? I have Nook Color on Cyanogen Mod 7..

Thanks!