I had the exact same problem on my Win 7 x64 after installing Logitech SetPoint. The problem only occured in my web browser though. Thought I'd mention it anyway since no other has, and the requestor didn't mention if problem occurs everywhere or in browser only.
I never noticed during the SetPoint installation, but it actually installs an addon (atleast for Firefox), and that damn addon apparantly creates scroll issues.
So my solution was to simply disable Logitech SetPoint addon in your browser and it worked perfectly again.