I had issues like this before. the kill a watt is measuring the draw between the wall and the power supply. If the the psu is not efficient it may be pulling more then the older 165 just because it it thinks it needs it. The 5830 is a power hungry beast but a decent 550 should power that system without issues. i would rma it (if you can). it may be that one of the caps blew inside but it is still working just not when you push it.