fire up a sniffer and see what it shows. I don't think your wifi card will work for capturing packets. Does it do the same thing wired? If it is install ethereal and run it to see what is going on.
Sorry for the late reply I've been out of contact for a while. I run a 100G and a 40G. 100 as primary windows and 40 as Linux. When I upgraded mine I just made sure that the disk was set to cable select, as it hangs off the secondary...
Here's an update. We all survived the trip. Turns out the place I'm renting is less than a 1/4 mile from the CO that has a dslam. I got DSL hooked up and back online for a while. Just need to sell my old house and find a job out here....
Unfortunately you have to replace the whole board. The GPU is soldered to the main board. You may try contacting Sager and see if they have a recommended repair depot in the UK.