I wiped my system and installed a different version of XP and for the life of me couldn't get the spinner to work in Windows. After trying 2 different installs of XP I thought I had to be missing something since it had worked before.
I have mouse 1 in the ini file and added -mouse to the command line and nothing was working. While playing around in the mouse settings for the bazzilnth time I was in the wheel section and for the hell of it selected Disable Detection for the wheel and the spinner started working right away.
I don't know for 100% if this will work on all systems but if you're having trouble making your spinner work in XP it's something to look at and try.
Encryptor