Static With Mbox 3 Mini and Macbook

[PXLpainter]

I recently got an MBox Mini with Pro Tools LE (running on a new iMac Intel Core i7) and it works okay most of the time, but I get a deafening HISS at times when monitoring. It's intermittent and not always with any particular program or sound source. It happens in all apps and system sounds. Sometimes it's just the trash emptying that makes it happen - sometimes it's a matter of pause/play.

Checked connections, etc.. all the obvious - not a physical issue that can be determined, unless I got a lemon MBox..
Any suggestions?

Thanks,
Jeff

[docscholl]

Curious - my Mbox 2 gives off static when I use phantom power.
Seems I have to press the buttom on/off several times or at least wait about 15 minutes before the static goes away.

Are you having your problem with or without the use of phantom power?