2003 manual transmission power loss

I just bought a 2003 new from the show room and it now has around 10,000 miles on it. Ive kept the maintence up pretty well, and the only real thin ive done to the car, is put in new jbl speakers in the back. Ive had an issue with power loss, like sometimes when i have the ac or music up loud, or even just my lights on, the idle will drop and then pop back up, or in the extreme case when i come to a stop, (with the clutch in... or in neutral ... or both)..... the rpm will just drop and stall out. then i have to start the car again and its good until i start again. then i pull over for 5 min and it works fine for about a month. Does anyone know what could cause that? or has anyone had a problem with that? when i bring it to the dealership they cant replicate it so im sol unless u guys have any clues.
thanks
greg

yeah, my cavalier has the same problem, I always found that it happened when I was really low on gas. try and keep your car above a quarter of a tank and see if that helps.

i have noticed that but it still does it when i have a full tank.. i just filled it up yesterday and today its doing it again..... help :)