Thanks guys, I'll wade into the manual. I know the Mbox is old, it's kind of all I have for the moment though. The idea is to buy a focusrite FW interface sometime in the future, but only when I have the cash (I'd have to sell a guitar or two!). I figured it was latency; just wasn't sure as I've had the same delayed monitoring on other interfaces, but not the tracking issue. Should probably look up the term 'latency' at the same time as I read the manual!