Wheel Mouse and scrollbar

[PowerM]

Hello
I have problem with wheel mouse in AccessXP, wheel not work for most outer form vertical scrollbar in runtime application.
If i click in raport it works, if i click subform it works, if i open IExplorer, word, ... etc it works, but not work in main form.
Its strange because it worked lately on that computer and it works on other computers.
I've tried to reinstall drivers - no effect.

Any ideas?
I've believe that is registry hack for that problem

Thanks
PowerM