Quoted from Spudgunman:#1 problem that will cause this is low line voltage, meaning that the power from the wall is poor. Before you mess with anything check to see if you have less then 120/119 volts, if so this is high likely hood of the issue. Stiffen up your neutral on the house electrical.
+1 on this I have to have my STTNG plugged into a completely different circuit than my other pins for it not to reset, and can not use my monsterr surge protector on it st all.
Do check all connectors - I also had a bad connection where wire was 90% out of the connector. Even after fixing this, still need different circuit.