Project Upgrade caused lag on android

Please, I made a game using unity 3.4 for the android platform. The game played smoothly but from the moment I upgraded to unity 3.5 it started having lags.
I chacked the quality settings and made everything there ok, but the lags stayed(though they eased up a bit). I also noticed that removing somethings and adjusting some functions reduced the lags a bit, but I don’t understand. The game ran smoothly with all those functions. Why does it seem like they are now too heavy.

Please, I need to know if there are any new features that might have caused this.

Without more informations it’s really hard to help you ://

Maybe check the release notes of 3.5.0 and higher cause I don’t know your real version to 3.5.0 or higher 3.5.5f3 ?