YEEEEEEEEEEEEEEEEEEEEEEES!!!! I finally found a working solution to the annoying problem!
Do as I describe below and you will have no more problems with the scrolling (that probably goes for all software - but I've tried Picasa and winamp). Please write a post and confirm if it works for you!
FIRST! - uninstall any versions of Intellipoint (you kan keep Intellitype if you want to)
1. Download Intellipoint 6.2 (do N O T install it) http://www.microsoft.com/hardware/mo.../Download.mspx
2. Use winzip to extract all files from the installer package - I suggest you extract to the desktop (keeping the file structure)
3. Go to device manager
4. Go to mice and pointing devices
5. Delete all mice AND their drivers, do a scan for new hardware or restart the computer (this step is only necessary if the method described below doesn't work - so only try it on your 2nd try)
6. If you have more than one mouse in the device manager (which is the case if you've bought the Wireless entertainment desktop 8000-set) verify which mouse that is the one to update by trying to disable the others one at a time (the 2nd mouse is touchpad in the keyboard)
7. Update the drivers for the mouse manually (by specifyfing the path to the drivers in the extracted package - eg. DESKTOP\IP32Eng18.104.22.168\ipoint\setup\files\ - use the "have disk-method")
8. Vista will probably not complain about the driver since it is signed and certified. But if Vista does - install anyway.
9. Verify that your mouse driver version is at least 22.214.171.124
10. Use your scroll wheel like any normal mouse!
11. Write a post here about your success.