This makes me suspicious, but only because so many people have had problems with aftermarket fuel pumps.
If your problem is fuel boiling, why do you think that you hear the pump sounding like it's pumping air? Wouldn't you expect the pump to still be picking up cool fuel?
Does this happen...
Do they think that the return line is dumping fuel into the tank, causing splashing and aerating the fuel that's being picked up?
What kind of fuel pump are you running? Is it in the tank like the original, or outside?