Apple Logic Pro /LogicExpress Discussion

So when I'm switching between projects, it prompts/warns 'you should close the open project if you aren't going to use it to save memory' or something like that.  I always do, I rarely/never have more than one open.  But on occasion, when I start the song it'll start skipping/generating some static-y kind of sound.  Even if I have made sure no projects are open and then re-open the problem one, it still has a problem, like it didnt clear out the memory.  The only way I can get it to operate normally is to close Logic and reopen it and reload the project.

This is on a relatively new MacBook Pro 2.4 with 2GB RAM.  The largest project has <10 tracks with a mix of midi/software and real instrument tracks.

Is this normal?  Am I doing something wrong or are there some other settings I should take a look at?

Thanks,
 
Bryan Lucas