[XTRazzer]

You could have an impedence issue.

Basically with 4-ohm single voice coil speakers, the amp either sees 2-ohm or 8-ohm on a single channel. If that amp isn't stable at 2-ohm in bridged mode then you can have problems like you describe (overheat or shut-down).

I would still be checking that I didn't have bad power or ground wiring.