Hi All, I'm having problems with my computer I built some time ago now. From time to time it will completely stop responding and need to be reset using the power switch (sound also hangs if there is any at the time). This will happen very frequently when the RAM is in a dual channel configuration, this has always been the case. In a single channel config the problem seemed to vanish though so I just kind of made do like that, this has worked for a number of months - recently though it's happened a couple of times even in this config. Instinctively it feels like a module coming loose, or losing connection with the motherboard, but I've reseated the RAM many a time. There's a couple of things that seem to make this more likely; Streaming Flash video (ie for TV catch up services) and opening uTorrent in particular. Although while running in single channel this was never really an issue, in dual channel I can get it to crash very quickly using one of these activities. I know this isn't a heat issue as I've done a lot of stress testing with pure95 and a gpu stress test I forget the name of. I've also ran memtest over night with no problems, and the HDD diagnostic tool from Samsung, again with no problems. Components in my system are listed on my profile - essentially, core i5 750, Crucial 2x2GB DDR 3, 9800gt, Gigabyte P55 board, Linksys WPM600N wireless, Samsung F3 HDD. Thanks for any help, I've attached the output from the SF Diag Tool.