Microsoft Wireless Optical Mouse, batteries...

Hi guys,
I have a Microsoft Wireless Optical Mouse v. 2.0a which is supposed to have very good battery life, but i'm forever getting pop up mesages telling me my mouse batteries are crtiically low, even a day after I replace them for brand new ones. I have the latest drivers for the mouse, but I keep getting the messages, some times many times in a day, sometimes once every couple of days. The battery level and signal strength are both high in the wireless mouse hardware profile in control panal. Is this a regular problem people have with these mice or is it just mine? Maybe someone had the same problem and knows of a solution?
Cheers!