Great Game, but lag issues...

The game itself is great. I downloaded it a few months ago to my MacBookPro and have had a blast with it. My girlfriend and I play the co-op option almost every time she comes to visit. There is one major issue though: it seems that after some time the file gets corrupted and begins to lag, so that the characters move in a delayed and jerky manner. I hace not been able to find any way to fix this so am currently reinstalling it (hopefully my save games wont be lost!)

moses27atdeis about LEGO Harry Potter Years 1-4