Wheel mouse won't scroll

[edj]

XFree86 Version 4.3.0 here.  XF86Config has the following:

 **********************************************************************
# Core Pointer's InputDevice section
# **********************************************************************

Section "InputDevice"

# Identifier and driver

    Identifier  "Mouse1"
    Driver      "mouse"
    Option "Protocol"    "PS/2"
    Option "Device"      "/dev/psaux"
    Option "ZAxisMapping" "4 5"

That last always gave me a scroll w/ the wheel; now, on Slackware 9.0, 
it doesn't.  The copy-paste function does work, however.  Any pointers?  
Thanks.

-- 
Ed Jabbour