Geez... umm... if his headphones are too loud (non-noise reduction) you might still be able to hear them loudly. Like ear buds. That would cause a reverb... but, if it unplugged that doesn't make any sense... maybe he has a bad case of tinnitus? It sounds like either a sound card problem, or someone on Vent is being a jerk.
I might sound like a crazed lunatic... but you can get your hands on a pair of 8800GT in SLI for CHEAP nowadays. Yet, they take up more juice. Depending on your bottlenecks, I would get the best card that won't be slowed down by your other parts, regardless of how much it costs... it will be sweet in the long run.
I have an Intel Q9550 (2.83 Ghz) that I OCed to a stable 3.825 Ghz with 4GB of nice Ram. I also use two 8800GT in SLI, but that is on it's way out. I recommend eVGA parts for almost everything and OCZ Ram.
Yeah... Movie Maker is the bane of all existence. I use Final Cut Pro ($$$) and Adobe Premiere Pro ($$)... yet, I DO think Movie Maker can be used for photo slideshows.... takes too long in Premiere or otherwise. Just search for "Video Editing Open Source" and see what you have. The trouble with Windows Movie Maker is your video drivers and such play a big part. There is TOO much room for error.
