Logitech mouse problem

Hi,
I have a logitech cordless "click" mouse on my single proc G5 powermac which works fine apart from one weird little problem.

Whenever I boot up the mouse sensitivity is set too high.

When I go into system preferences it shows the mouse sensitivity set to 6 - which is where I've set it - but the mouse behaves as if it's set higher than this.

Now if I just click on the Tracking Speed slider - without even moving it - it suddenly "remembers" the correct mouse sensitivity and starts behaving properly.

Silly little problem, but I get fed up with having to go into system prerferences every time I boot up. I've tried every available USB port and it makes no difference. Anyone experienced anything like this before?