Reply to Crackling noise with Stealth Control

Hi guys little help, I have had my stealth control for around 3 months now, loving every minute of it, I have the simplest of set ups, running it straight into my laptop (dell inspiron core duo i5 running 64bit winds7) last couple of times I have played I get a crackling distortion coming through when I get to a peak of a mix or when I use the effects. I have tried re-mapping it and also have tried using other usb ports still get the same thing, any help would be appreciated...