Have you tried reinstalling the driver?
Try setting up another admin user account to see if the same problem continues. If Back-to-My Mac is selected in System Preferences, the Guest account will not work.
If the problem is still there, try booting into the Safe Mode. Shut down the computer and then power it back up. Immediately after hearing the startup chime, hold down the shift key and continue to hold it until the gray Apple icon and a progress bar appear. The boot up is significantly slower than normal. This will reset some caches.
Tried a set a fresh admin user account, but same mouse issue in there too, even if it is the only account 'running'.
Got into Safe Boot and found the same issue (double click sometimes results from single clicks).
Any other thoughts please? Usually I've got a powered Belkin USB 2.0 hub in the mix with this mouse, but even directly plugged to the MacBook Pro the issue is present and obvious within seconds of use.
Also, the mouse model in question...
I see no OSX drivers to get since I don't believe they exist. Should be plug n' play I'm thinking.