Chevy Colorado Starting Problem

I have a 2007 Colorado, 4 cyl, automatic 125000 miles. Once or twice weekly the truck will crank but will not start. It usually occurs after driving long enough to get engine to operating temp and I shut off the ignition. When I try to re-start it will crank but will not start. If I wait ten to fifteen minutes it will start just fine. I took it to the local Chevy dealer where they kept the car all day and could not duplicate the problem and they found no error messages to suggest this problem. Anyone had any similiar experience with this model? Thanks, lleach1