Apple Logic Pro /LogicExpress Discussion

I'm a long time user of Logic from the old Emagic days Now that i have
gotten used to the new workflow etc, with apples ways of doing things,
i am finding that since i installed my logic 7.2 upgrade my old song
sessions are playing distorted. Has anyone had this problem and if so,
how do i fix it other than re installing the old version of Logic 7.1
which i had to go back to in order to finish my projects. 

Chico
Rizz One Entertainment,
Junior Vasquez Music,
Virgin/EMI
Robbins Ent
Nervous Records