Mouse wheel scroll lines reset to 1 on logon

Every time i log on to any account on my Inspiron 5150, the mouse property
that specifies the number of lines to scroll for each notch/step the wheel
is turned, is set to 1 (which is too low to be practical).

How can I make it stay at the value I want (typically 3)? What could cause
it to be reset (winlogon.exe)?

I have also tried changing the property in question using TweakUI, with the
same result.

dOinK
WinXPProSP1 all updates
Inspiron 5150, USB mouse