PT 10.0.1 Bad Distortion on Output

[TVA]

I'm running PTHD 10.0.1 but using an Mbox Mini 3rd generation hence posting here instead of HD TDM/Native forum. Using Dell XPS L502X, 8GB RAM and I'm getting some strange behaviour. Randomly the output will become heavily distorted as if white noise had been added to it and it had been put through comanaut voise or similar. I close PT and relaunch and it comes good. I have been having another problem which may be connected whereby PT can't find the MBox mini and so won't launch. This happens intermittently after a reboot - I keep a copy of the driver on my desktop and remove and reinstall drivers which fixes the problem everytime. The digital noise thing is becoming a real problem though so if anyone has any ideas they'd be much appreciated!