Had a Logitech G7 now for a few months from Scan and it's developed a fault. Every so often it just locks up completely for about 4-5 seconds, then back to normal. Sometimes it can do it persistantly for a few minutes then go away for hours.
I've done some reading around and others are having/have had the same issue and it's been suggested that there's a fault with the battery connectors. Some people have claimed that changing frequency on their wireless router has solved it but others such as myself have confirmed they have no wireless gear that affects it. A quick scan with my PSP shows that there is only one wireless point near my house and I know that's been there since I got the mouse.
So, the upshot of the thread really was to see if anyone else has experienced it and if so what they did to resolve it.
I'm probably looking at an RMA to Logitech though, very dissapointing for a very expensive piece of kit.