I used to have one a few years ago where that happened. Fixed it in the end by installing the MS Wheelmouse software. I suppose it might have been a corrupted driver or something like that.
I now use an optical wireless Memorex MX4350RF which was very cheap on eBuyer. Takes a little bit of getting used to at first, but it is 100% compared to previous mice. Doesn't feature there currently, but there are several similar for <£15.