Hi Mark,
I would suspect the cord or the switch. With any of the Milwaukee quik-loc cord tools I would look very closely at the connection between the cord and the saw. This cord system has always been a weak link on the Milwaukee tools. The coupling on the cord is the most common part that fails but the connector on the tool side will sometimes go bad too. If the cord and wiring checks out OK then I would agree that the switch is the culprit.
The cord is part #48-76-4008, the connector is part #14-46-0155 and the switch is part #23-66-1491. All of these parts are available from http://www.ereplacementparts.com.
Good luck with your repair!
-Mark