When I replaced my filter, I did exaclty what stazi did. Cept, I basterdized an old aircompressor hose with a tire valve end, stuck it right on there, and the gas shoots out the hose into a bucket.
One question though. Did you relieve pressure in the tank by unscrewing the gas cap? If you did, did you tighten it back down after words? If not, the tank (since it was under no pressure when you changed the filter, will not pressure back up if thae cap is loose. Check that. That sounds like your problem there.