I've had this receiver for about 2-3 weeks now and up until now it's been flawless. But the other day, while playing my iPod via the line-out on it's dock, at a reasonable but hardly loud volume level, the protection circuit kicked in and turned the machine off. So I waited 5 minutes or so and put it back on and everything seemed ok. But today, I can't get more than about 2 minutes out of the machine before it knocks off again. Playing Dolby Digital sources, I noticed that whenever the sound reached a bit of a peak musically, the Denon would switch off again. The volume is hardly ear-bashing. At very low volumes it seems to work fine, but my TV sound provides more excitement at the moment. I've unplugged everything that's uneccessary and left it with just the coaxial in for DVD and the speaker output. It still turns itself off as soon as it gets excited. I must stress that the volume isn't overly high at all - it says "-20" on the display, which worked fine last week and the week before. Is there something obvious I'm doing wrong, or do I need to get it back for an exchange? I'm using Celestion AVF-302 for the front speakers, the AVS-303 pack (centres and surrounds) and a Mordaunt Short MSW-20 sub - all of which has been tested on another system and works fine. The wiring is all correct - there are no strands of wires touching anything and the banana plug fittings on the front speakers are all secure. I'm totally confused.