I was having a problem with my 360, that every time I started it I would get error 74, but after a restart it would work perfectly. I couldnt get any sense out of MS on the phone (as it would always start to work as they were troubleshooting it), so I just decided to leave it be, it wasnt that big a deal.
Anyway, the other day I was re-arranging stuff in my room, and a magazine fell down the back of my entertainment centre, which I failed to notice. I have been playing skate for the last few days and theres been no problems. The magazine had fallen and covered almost the entire length of the fan vents on the back of the 360. When I noticed, I quickly removed it, and was worried the 360 might be damaged. Instead, it has actually stopped my 360 from E74ing every time I switch it on. It now works as normal. I think I will struggle to ever understand the crap design decisions MS made for this product. I'm glad it works as advertised now though.