Stalls while driving

The vehicle will stall out while driving. When I try to restart it the engine sounds like it is trying to catch but does not. The engine will not restart for about 10-45 minutes. There is no check engine or any other warning lights on before the stall or after the stall. Prior to and after the stall the vehicle runs fine. The problem could happen again the next day or it could go a couple of weeks to a month before doing it again. My mechanic had it for a whole week end. The vehicle didn't stall out and the computer showed nothing. We were both leaning torwards the fuel pump, but he does not feel comfortable just throwing one in and have that not be the problem. Today when the car stalled out, I gave the fuel cutoff switch a good whack. I heard the switch "rattle" but the button didn't pop. I gave it another good whack and the button finally came up. After resetting it 2 times the vehicle finally started. Have you ever heard of a cutoff switch going and could this be the problem? The only other thing that I can think of at this point is that someone sabbotoged my fuel system.