I don't think this a Windows 7 problem.
My Razer Deathadder does the exact same thing. It (same exact mouse) did on my old rig with XPPro as well as my new rig with Windows 7.
Sometimes (but not always) the problem can be reduced by playing with any of the Razer scroll wheel settings (turning the wheel light on or off, turning universal scrolling on or off) but the problem always returns.
It began shortly after I updated the Razer drivers to fix their left button double clicking issue. That's the issue that they spent a couple of years blaming on the customers, before they quietly released a driver update that fixes it. Now the left mouse (trigger) button works fine but the scroll wheel does whatever it wants too, every single time its touched.
Scroll one notch down, it scrolls itself two notches back up or more. Scroll one notch up, it scrolls two notches down or more. Want to look at pg3 of a PDF or Doc file? Good luck, you'll have to look at pages 2, 5, and 7 repeatedly until you give up and use the arrow keys.
Use your scroll wheel to change weapons classes in an FPS shooter game? (COD 4/WAW and BF2BC2 in my case) Fat chance. It will rapidly scroll through all of your weapons classes before returning you to your first (empty) weapon, or it won't bother to change anything at all.
It took almost two years for Razer to acknowledge the double clicking problem (I have another Deathadder torn apart in a drawer from a vain attempt to fix that mechanical problem that turned out to be a driver issue).
Razer is also still not admitting that some people are having a major problem getting the drivers for the Microsoft/Razer Reclusa keyboard to work in Win7Pro x64. (default Windows 7 drivers do work - but no Razer kybd control icon shows up)
So I'll repeat, this (these) is not a Microsoft or Windows 7 issue. They are Razer issues that seem to effect only a very few Razer customers. Good luck getting any support out of Razer on them anytime within the next two years...
I'll be going back to Logitech, as soon as I can afford too.