A couple weeks ago, the Enclave started having a problem cranking up and running after putting gas, any amount of gas, in the tank. After putting gas in the tank, the engine does not start as it normally does, but rather seems to have a clicking sound coming from under the hood while trying to run. The battery is fine and the motor is being cranked over just fine. After cranking the engine about four times, it will run just fine. This ONLY happens after pumping gas into the tank. Once filled with gas, the car starts and runs perfectly until the next time I get gas again. Has anybody ever heard of anything like this? Any ideas what could be causing this? The dealer service writer said something about the charcoal filter in the fuel system. Thanks.