I think i know exactly what your experiencing. Go to your device manager in windows. There is a section for HID compliant devices. If you disable them it will not affect the functionality of the computer and will get rid of your little lag spike u get every few seconds. Also since your video card applies to this... try getting nvidia forceware 266.58, as its hands down the only driver that actually works GOOD with ffxi. Trust me... long time figuring this out.