As a critical part of the navigation system on my boat, I use a Dell Inspiron 600m laptop interfaced with a handheld gps. I use Capn software and electronic charts.Periodically when I boot the computer, the cursor goes wild, flitting all over the screen and is totally uncontrollable with the touchpad, thus rendering the computer useless. This never happens when I have the computer at home. I have a second identical laptop which I keep in my office at home, but which comes along for redundancy on long cruises and the same thing periodically happens to it, again only on the boat.Any ideas on causes and cures will be appreciated.Gary WyngardenS/V Wanderlust h37.5