That problem was covered under a recall some time ago. The fuel filler valve has a problem and the entire fill 'neck' gets replaced under the recall IIRC. The flap that keeps gas from spilling out of the car in the event of a rollover is faulty and causes gas pumps to shut off because the flap is obstructing the flow of gas down to the tank. You may still be covered under the recall, talk to your local dealer and see what they say.
Unfortunately it isn't an easy job to do yourself as the entire gas tank has to come down and then the filler neck has to be replaced.
