a couple times lately (not every time) at the gas station I will fill the tank but the gage only reads 3\4 full! (which is the actual amount of gas... the pump just stops as though it were full) Any ideas on why that is?

 

I know it goes agains all instincts, but pull out a little
sometimes if the nozzle's in too deep you get turbulent flow which causes a pressure backup and makes it shut off prematurely.
and the last thing ya want is premature termination