Exit games while playing...random occurance. Any ideas?

[alortegac]

I have had my raspberry pi for some months now, but since there very beginning sometimes the system would exit while playing the games, like resetting or disconnecting for a second...then screen goes black for second and then back on to the ES game list (like an when exit game). I would then restart the game and it would play well again like nothing happen. It seems like a random thing that happens only sometimes, not only in one game, not after an specific period of time and not on an specific emulator. It looks like a system - hardware issue to me....any thoughts? Your input is greatly appreciated, thanks!