Logitech MX-700 Misbehaving

Lately I've been having more and more trouble with my mouse. When I attempt to highlight something to copy or delete it seems to keep forgetting what I'm doing on the middle of the operation.

Similarly it also seems to be interpreting single clicks as double quite often. When I click on a window heading it about 70% of the time explodes to full screen.

Thinking I had a driver problem I downloaded and installed the latest driver from Logitech to my Windows XP Pro SP3 with 2.0 GB of memory and a 3.2 GHz single hyperthreading CPU. The new driver didn't fix the problem.

This problem started well before SP3 was installed so it's not that.