I have a very strange problem with my Fujitsu Lifebook S6520. Windows XP was blue screening and reporting videocard error. The system would also freeze and dump soon after booting ad I had artifacts all over the screen. I thought it was a video driver issue or perhaps my S3 430 ulp was malfunctioning. After playing with drivers, rolling back etc. there was no change. I pulled out one of the 2gb ddr3 pc8500 modules and believe it or not everything was fine, the system was rock stable. So I thought, oh bad memory module. I purchased 2 matched OCZ 1gb ddr3 pc8500 modules and installed them and the problem returned, the same problem! So I pulled the module out of the same slot as before and everything is fine again running on a single 1gb module. I checked the slot and everything appears fine, no dirt or dust, all wires leading from slot to motherboard appear to be connected and not shorted, and all little connectors appear to be seated correctly placing proper spring tension for proper connection, so I am at a loss. The modules are good; if I put them in the good slot everything is fine. Has anyone ever heard of an untampered with (before now) memory slot going bad suddenly without reason? If anyone can think of something I would appreciate any ideas, I do not want to pay for a new motherboard if there is another way. I could run on one module however I do not know the entire extent of benefits of dual channel with ddr3, not to mention if something is going wrong I could run into new problems. Thank you in advance for any assistance or thoughts.