Motherboard problems GA-6VXC7-4X-P

Hi,
Somebody gave me this mothrboard and the CPU. So far, I have two problems. First, my mouse is an optical USB and I can't make it work. In the BIOS, three configuration possible for USB legacy support: 1- keyboard 2- keyboard and mouse 3- disabled. But my keyboard has a ps2 connection. If set the USB legacy support to disabled, Win98SE doesn't find my mouse. And if I set it to keyboard and mouse, Win98SE "crash" (a blue screen pop-up). So, how can I make my USB mouse work in the USB port. My second problem and this is one is more serious. I can't load Win98SE if both my HDD are connected (Hard Disk Drivs: 1- DiamondMax Plus 60 7200rpm 20 gig at IDE model: 5T020H2d 2- Quantum FireBall Plus 3.5 Cx Series 13.0 AT gig IDE 5400rpm). I have tried both HDD on another computer under the same Win98SE and everything works fine. I have tried my main HDD (maxtor) with another HDD and it also works fine. Both my HDD are detected in the BIOS. But when normally "starting win98" should appear on screen, I only have a blinking cursor. One final thing, on the motherboard, the letter "P" is on it like it should be the model P, but it looks like it is not the model P. I'm saying that because on the manual it's written that the model P should have a frequency ratio up to 12X, but on the motherboard, it is only printed up to 8X. Anyway, I only hope you could help solve me HDD problem and, if it possible, my mouse problem too. Thank you. P.S. I updated the BIOS with the last version.