Vista - Mouse problems

Hi

I have posted on this before but did not get a solution to my problem.

I am running Vista Ultimate.

I have a Logitech mouse, and when I go to Control Panel and alter the speed
that the curser moves across the screen it only woks until I reboot, then it
is back to the default setting, how do I get it to keep the setting I change
to?

I have been recommended to update the driver but there is no Vista driver on
the Logitech site, it is installed by Vista.

Any help suggestions appreciated.

thanks

Daniel