Thank you Wings for the input. I cant say that I have overfilled the tank.
After some research I did find three type of filler necks. The one on my car has no vent tube as opposed to the other type that has a vent tube at the filler opening.
So Im not sure if this could be the problem. But Certainly could be a consideration.
I don't believe i did. This happened with a 1/4 tank. If I over filled it I would think I would be having issues almost immediately.
Not that it couldn't happen .....
Shown below is the New style Tank



Old style tank