Apple Logic Pro /LogicExpress Discussion

I'm sorry, I meant to write I use 10.3.5 as Logic Pro only runs with OS 10.3.X.
I got an email saying that the noise is due to a bug in Logic Pro, and that I should set my 
audio buffer to 32, relaunch and then set it back to 512 and relaunch. For the time being 
this seems to have worked out my noise issues, but Logic still skips during real- and 
offline bounces. Does anybody know why ? I can't start my arrangements in Logic 6 as 
reviously described, so I'm in big trouble as I soon have to send all of my arrangements to 
mix.
Thank you
Sarah