Wireless Mighty Mouse weird behaviour

Hi,

MacBook white 13", leopard 10.5.5.

Bought the wireless mighty mouse, worked great for 30 minutes on my MacBook at work.

Suddenly, the movement is now so slow & stuttery that it's useless.

The wired mighty mouse works no problems on the table.

Re-paired the mouse, removed batteries, system fully updated, nothing works.

Any suggestions more than welcome.

Thanks,
Pete.

Forgot to say, if I use the mouse on a glossy book cover it works now, but that's it !