Keyboard problem with SoftICE on NT
 

After I updated my hardware I have problem running SoftICE on my computer. Sometimes I got '6' and '2' when I press cursor keys or keyboard works like ctrl+alt was pressed down. My keyboard is a simple PS/2, and mainboard is EPOX 8rda3 with NForce 2 ULtra 400 chipset. I've tried SI 4.0.5, 4.2.7 and 4.3.1 on 2000, xp and 2003. SoftICE on 98SE works without problems. Do you know what is the reason?