Sounds like a short circuit might causing the amp to go into protection mode. It could be a problem with the right channel on the receiver or the right speaker or the wiring on the right side. Replace the wiring to eliminate this as the cause and switch the speakers. If the problems starts happening on the left side, it is a problem with the speaker. If the problem continues to exist on the right side, your receiver is shot.
Also dont run your laptop or iPod at more than 60% of its max volume. This will ensure that you are not over-driving the pre-amp on the receiver.