I know this sounds crazy, but do you have the gas cap that has the vent that you can turn on and off on top. If so, have you tried loosening the gas cap from the tank? Sometimes, the vent cap can go bad on ya, and even if it is set to the open position, it does not vent properly, you end up with a vapor lock and it shuts the engine off.
Whaaat?? Thats crazy!!
I know, I know. Thats what I said when the guy at the Honda shop told me that, but he was spot on. Bought a new cap, and its still running like new.