Jensen MP7610 power cuts off frequently from time... (by 2 users)

This leave's me extremley puzzled. FYI i am fairly knowledable on car sterio and systems. I installed Jensen MP7610 in my friends car along with an amp and subwoofer. Every time he hits a bump the power to the radio cuts off and then poweres back up a few seconds later. I am Almost positive connections are correct, i went by the manual, double checked tripple checked............. and as of right now i left the RCA cables plugged into the back of the radio but disconnected them from the amp. I dont know what kind of a difference that would make but im seriously trying everything to my knowledge and im just lost. Please, any suggestions would be extremley helpful

Thanks.