microsoft intellimouse cordless optical gone crazy

Hi All,
My mouse has gone mad. To fill you in; clicking next on internet explorer goes to next page, & opens another identical page as well; left clicking in the address bar brings up a 4 way arrows with a dot in the middle. The same applies in outlook. In my Sign making software a left click now brings up a large open hand which jumps to different parts of the screen when you click. This is driving me crazy. have scanned with several antivirus programs, error expert, hijack this, etc., & nothing shows up. Any help would be greatly appreciated!