Slow mouse response - help

I'm using the Microsoft Wireless laser Mouse 6000 and have installed the Intellipoint drivers for OSX but, i find that the mouse response had degraded lately, most specifically, the left click has to be pushed two or three times each time before it actually selects what I'm trying to select.

I've reinstalled the drivers, have fresh batteries, cleaned and checked the mouse and still seem to have the problem.

Anyone have any ideas on how I can fix this?

I'd check using another mouse just to confirm that the problem is with the mouse, not elsewhere. If it's confirmed to be the mouse, then I think the micro switch under the left click is failing.