Intermittant Audio noise in Logic Studio?

[logicpro7]

Hi guys,
I am have some trouble with Logic Studio 9.

Sometimes when playing a project in Logic the Audio will break up and make a crackling/stutter noise.

I have to stop playback and try again until it plays properly. Even sometimes when bouncing down a complete track it will record the noise/stutter.

I am running Logic Studio 9 on a mbp with 8GB and Momentus XT hybrid 7400 drive and a Apogee duet2.

Cheers!

 

[logicpro7]

Oh, i am also getting a delay out of sync issue when looking at the arrange window the music is out sync with the onscreen wav/midi