Common issue related to heating as far as I'm aware and I had the same problem with one of my units. I was going to see if putting small heat sinks on some of the chips would help, but I ended up taking the system apart incorrectly and I ended up just tossing it. Not a huge deal, I ended up getting another unit that works fine for about ten bucks.
Hmm that would make sense. I noticed thermal paste on one of the chips and just figured there was plenty still on the heatsink, I'm gonna put on some Arctic Silver and see how it goes. Thanks.