getting unwanted signal when engaging record
 

Working on a new MBP with PTLE 7.1.1 and mBox 2...

I'm getting a ghost signal when I engage record on a track. I'm recording a guitar at the moment, and everything is fine on my end. I can monitor through the mBox and hear it in my speakers, but as soon as I engage it, there's a pop in my speakers and the meter jumps up to just below the peak mark and stays there. There's nothing audible besides the pop.

I've checked my I/O settingsand everything looks correct. Anybody else have this issue?