System freeze on kernel 2.4.18 unsing /dev/psaux

I'm using slackware 8.1(2.4.18) with a Athlon thunderbird 850 mhz, a
Asus A7V133 (Via KT133A) and a ps/2 Microsoft IntelliMouse Optical and when I use the mouse, the mouse and the keyboard freezes.
I've got the problem first in the X11/KDE, but I've tried to exec a
"cat /dev/mouse" and "cat /dev/psaux" on the console and it freezes too. I've tried a genius netmouse and happened the same thing. The computer seems to be working but the keboard and mouse do not respond, is not a system freeze but only the keyb and mouse.
Before the install of Slackware 8.1 I was using the 8.0 (kernel 2.2.19
and 2.4.5) and every thing is fine!
Do you have any help to me ?

ps.: the keyboard is a Genius KB-18M standard mini-din (not usb).

Thanks in advice,
Edmilson Junior