Vista - Mouse diabled on start up

Hello there,
I bought a laptop mouse which works fine all of the time - except when Vista
starts up.
On start up the mouse is disabled and I unplug the USB plug and re-insert
into the same socket.. the mouse is instantly alive and working.

Now, I would have thought that once finding the mouse, it would recognise it
next time Vista was started - but it doesn't - even when the machine is
untouched i.e.. the mouse connected during power down and power up.

Anyone have any answers as to why this is happening and how I cure it so
that the mouse is recognised at start-up without unplugging and reconnecting?

Thanks in anticipation.

Allan