Ok, I know this issue is long standing, and I'm irritated with it too. However after doing some proper research myself BEFOREHAND, I have come to a few conclusions and comments to add.
First off, Winamp is not to blame as such. I would think that when winamp first started that the basic mouse control programming worked perfectly...so why mess with it? They have left it alone all this time because for a lot of people it works just fine.
Sadly, for people such as myself with a Microsoft Wireless Laser Mouse 5000 series (and other MS mice), we still have this odd scrolling problem. So, on to the REAL problem and the only two solutions.
Even though it is a programmer's duty to test out every bug possible so that nearly everyone can use their software without problems, sometimes some bugs just aren't easily fixable. What we are all dealing with here, is bigger than just winamp, so STOP hounding these poor souls and think outside the box. Winamp is NOT the only program with this dumb down-scrolling problem with MS Mice. I, for instance, can't use some java/or flash applets in my browser. The browser will scroll perfectly, yet in the applet scrolling functionality works just as badly as winamp. Examples? The only two I've noticed so far (don't laugh) is the FarmTown app on Facebook, and the interactive radar on the Weather Channel's website. Both suffer from problems zooming in and out using the scroll wheel.
And now on to the source of the problem. Think of it like this. You have the newest version 7 intellipoint software installed and most of your scrolling works; however, winamp and a few other programs and apps just won't work.
Common sense? It tells you that the problem must lie with 1 of 2 possible parties.
1: The problem could lie with older (dare I say Legacy) apps like Winamp that have been around for a while, and programmers that are comfortable using older programming styles...aka, not keeping up with the times...by learning all of the new, and sometimes stupid, changes brought about by new Operating Systems. The new API changes in Vista and Windows 7 apparently clash with Winamp's usage of the mouse scrolling. Notices Winamp doesn't inherit it's mouse usage from the OS so much as it has some options built in. Look in your preferences under "Playlist" and you'll see the scrolling options. I noticed when I go to Intellipoint (Microsoft Mouse is the desktop shortcut) and I fully disable all vertical scrolling that my scrolling in all the previously working programs stop (such as browsers and other progs). What interested me is that every program and app I had the scrolling problem in (winamp, FarmTown, and the interactive radar) all continue to scroll and they STILL do it badly. These apps must have built in control over the mouse, and that should probably be cut out to let the OS take over.
2: This is the best solution, yet the most impossible to make happen. Microsoft is *GASP* at fault. If they had a programming team anything worthwhile, they would happily open beta all software and let the world find their problems so they can fix them. You wouldn't believe the number of forums out there for other programs other than Winamp that are complaining about scrolling problems. And how many of them have been sent to MS to fix? Probably all of them. I even saw a TechNet forum where the MS Rep tried to blame the problem on out of date VIDEO drivers...HA! I SCOURED the MS Knowledge base with only 1 true mention of scrolling problems, and they claim it only happens with ps/2 connectivity and some special method of installing which escapes me at the moment.
The results? Microsoft is a freaking GIGANTIC company...who wants to earn as much as possible, while saving money all the while and pump out software as quickly as humanly possible. The problem is that I'm sure the workers of MS are overworked and pushed to the limits so that simple problems are overlooked and swept under the rug. Problems like our simple scrolling problem. A simple programming fix should be available on THEIR end to add backwards compatibility to the Intellipoint software. Instead they silently (not a real claim by Microsoft...just making a point) claim that Application Programmers must keep up to date and fix problems on their end. It isn't MS's responsibility to maintain support for aging software standards, so in order to save money, they leave out support for certain old wisdoms and make people grow up and learn new skills.
Something as simple and widely used as the mouse and GUI should be at the utmost supreme high level of important stuff for Microsoft to care about...after all, that IS their main business. The Mouse and GUI make the Operating System...word processing takes second rung to that, and yet MS keeps missing the target.
What a shame.