Do you try to delete music files? In most of situatuian (I have the same problems) music files was too big. For example in my Miracle of Sun, I don't have music files, because it gives my... out of memory (because tileset is super big: 3200 tiles = 430 kb + 50 kb for level).
Also many levels have transperting and REFLEXED tiles (yes, it is very dangerous for memory: avoid this)