Wireless Mouse scrolling problem.?

Earlier today, I was using my wireless mouse just fine, and then it got slow for some reason. EXTREMELY SLOW at scrolling. I looked at the mouse "vertical speed", which was set at "3". I put that up a lot higher, I think now it's set at 100. So, that's weird, and I would really like to know what it is originally set at. But now, when I open the video editor Vegas Pro 9, I can't zoom in with the mouse wheel. If I hold the mouse wheel and scroll, I can move it side to side, but I can't scroll and zoom in the timeline. What happened?