I have an '04 V70. This am, I stopped to refuel and the tank wouldn't take fuel. The pump clicked off as if it were full and then the fuel backed out of the filler and onto the ground. I assume something has failed/clogged in the vent system. I was only able to pump about 1 gallon before I stopped because it seemed most of it was going on the ground. I really need fuel - the tank is very low. Any ideas? I tried just partially plugging the pump into the filler rather than sealing it tightly but that didn't seem to help. This had not happened on this car before.