Windows 8 - Cursor issues

I have installed Win 8 pro, 64 bits, on my new Mac Book Air, using Boot Camp. Everything works fine. Somtimes, while typing in MS Word the cursor jump suddenly to other area of the screen. Its happing every few minuts. I checked it carefully and i am not toucing the built-in touch mouse at all while its happen.

Please help me.

Thanks,

Indisg