Microsoft Mouse not working on Mac

I've just converted to Mac and bought a Mini. I plugged in my Microsoft Optical Wireless Mouse 2000 and it worked fine. But when I installed the relevant software Intellipoint 7.1 for Mac the mouse became very sluggish. I uninstalled the software and its fine again. What do i need the software for anyway? And could the problem have been cause by me installing the software whilst the mouse was still plugged in?

If it works just leave it be. Depending on your Mini model, it has Bluetooth and obviously the Mini is speaking to the mouse no problem.

On the subject of mouse, my cursor/pointer keeps flying round the page or dropping off the page when trying to navigate every now and then. How can I stop this, its the optical mouse that came with the imac.