Volfenhag ZX8300 on with radio, off with cd or mp3...

I just installed this 1200 watt, 4-channel amp with a 1.5 farad capacitor, and 2- 1000 watt Volfenhag subs. I hooked it all up and everything seemed to be good since the subs were pounding with the radio on. I then hooked up my MP3 player to the aux in and the amp and capacitor turned off. I switched back to radio and after a couple of seconds, the amp and cap powered on again. So I tried a cd and the amp and cap powered down again. What gives?

All fuses are good, the ground is nice and tightly connected to a sanded down bare metal surface in trunk and the powere wire looks all good. The system sounds great with the radio, but completely shuts off for cd's and aux-in. Any ideas would be greatly appreciated, I can't seem to find much help anywhere regarding this amp. Thanks!