Re: 8x card stuck in 4x mode?
From your bug report, the NVIDIA driver is detecting an 8x AGP rate, yet your AGP driver is putting the device into 4x:
AGP: Putting device into 4x mode
This looks like it might be an AGP driver bug, or perhaps the AGP driver is intentionally setting 4x to workaround some other problem. I'd suggest verifying that you're using the latest motherboard BIOS and also to test with a much more recent kernel.