Choppy Audio
I had a problem this evening with choppy audio - but this time my problem turned out to be something simple.
The optical audio cable connecting the XBox 360 to the receiver was dirty, and so it wasn't making a good connection. This caused the audio to drop out for a few milliseconds every now and then. What it sounded like was that the computer wasn't able to keep up with audio recording and was causing dropouts, but the problem was refreshingly low tech.
On a related note, I'd been using some cheap S/PDIF optical cables I bought off eBay, but their plastic ends on them have worn down and now they don't stay in place. This leads to a bad connection, or them simply falling out. I wouldn't suggest Monster Cables but a step up from the cheapest seems like a good idea.