I support GilesConstant.
Having spent about two months trying to fix the Wireless Mouse 5000 problem, much of that time with Microsoft support. Before contacting Microsoft I tried all the obvious mouse specifics, batteries, interference and drivers. Then I tried many other tests.
The problem proved to be independent of operating system, security software, batteries and other USB hardware. At one stage I had a marked improvement by installing a completely different architecture graphics card, within seven days the problem re-emerged.
The problem has been finally solved. I had been very misled by the Microsoft claim of a 30ft wireless rangeand therefore did not consider there would be an issue in this area. WRONG, by moving the receiver from the back of the Desktop computer to the front the problem disappeared. This move removes the case metal shielding of the receiver, raises the signal
level to the receiver above a marginal level which in turn will reduce the prospect of interference.
The two batteries in the mouse are connected in parallel to double the battery life, removing one will simply halve the life, as to why this might improve the mouse operation one can only guess that somehow this changes the RF signal level/pattern by a small
amount and thus moving away from an otherwise marginal signal condition that will result in variable operation.
I have now discovered others who have moved the receiver to the front get the same result, therefore my advice is that this should be the first move in correcting the problem.