It actually happens to me a couple times a week. I do the towel trick for 10-15 minutes until I get the two overheating flashing lights on the left side, let it cool down and then it's back to normal. Very annoying.
It's been happening for about 4 months. If it would just quit fixing itself, I'd send it in, but I always get it back working relatively easy.
If it's an E74, I think it's a scaler chip problem. If you don't want to do the towel trick, you'll have to send it in, but I've heard that this isn't covered under the 3 year warranty, so you'll probably have to pay for the repairs.
Hope that helps. Good luck.