crackling sound after half an hourish

hi can somebody shed some light on why after about half hour of performance in cubase 6 i start to get a crackling sound. im running it through a focusrite saffire pro 14,

Maybe your processor is throttling down due to heat issues?

As you have not posted any details that is just a pure guess!

Does closing the project and re-opening it fix it? I get this once in a while. Not sure why, but that is how I usually fix it.
HTH
J.L.

there’s an entire thread to a similar issue, may be yours and that one are related:
http://www.steinberg.net/forum/viewtopic.php?f=19&t=9423

my presonus fp10 does that sometimes if my windows 7 has been in sleep mode…
the music crackles and starts dragging.
easy fix…just reset my computer and get back to work. …zimmy