Here is a pic of the latest episode. The first time actually burned a big hole in the gasket above the float. This time is was just a little spot on the gasket and the float is all black in spots, while the other side is pristine.Time in between incidents is about 2 years and less than 1000 miles. Gasket was replaced with a new one.
Interesting note repeating from an above comment. The float does not leak but is about a quarter full of fuel. Both times!