I cannot use my USB mouse because USB 2.0 (NEC chipset) is detected as 1.1. Shall I use ehci instead of uhci which is default?

I used Knoppix 3.1 or 3.2, kernel 2.40.20-xfs.

BTW I got same problem on SuSE 8.1 (2.4.19) and I had to compile 2.40.20 with some 2.5 patches for ehci to solve it.