Buzzing and sound cuts off after exporting set

[Illuminator]

Hey all I have had this problem for a long time, and have tried nearly everything. Uninstalling, reinstalling, adjusting the sample count, etc etc.

Basically, everytime I play a set on live and then export, the exported wav file has a few issues

1: I get a long loud buzzing sound that overlays on top of the recorded audio, it can last for a few minutes and completely kills the sound

2: out of nowhere, the sound just starts to fade out, and disappears (even though there is a track playing, no audio is coming out)...after a few minutes it comes back in again

Any troubleshooting tips, or similar experiences I could relate to?

Thanks all

[Spectrumdisco]

What is your set up?

[Illuminator]

Laptop running windows 7, 64 bit, 2.2 amd quad core processor (intel equivalent), my interface is connected to an APC 40. All sound is sourced into my headphones, i have no other audio outputs