Ray Darr,
My fault, I misread what you wrote above. I thought you were not having problems with the wired side, just the wireless part.
After rereading what you originally posted, I would go in and completely disable the Wireless side, since you are not using it.
Also it would help knowing about your hardware. What Motherboard and NIC are you using?
I would hook another computer via CAT-5 and see if the second comp loses the connection at the same time as the current comp does.
That way we will know if the problem is the Router or your Comp.
Take Care,
Richard