I had a 150mW Lasever green at the first SELEM. When I got home and fired it up I had a green flashlight. The adjustable lense had vibrated during the trip enough to rotate the lense and screw it all the way back to the laser aperature. It has two indentions for a "key". I just to a pointy tool and wound it back out. That is probably what happened to yours.
Very nice it is not broken.