Symptom: Leaking in between the tank and the bowl when the toilet is flushed. This is a power flush toilet. Usually when you have a leak in between the tank and the bowl of a toilet it is either the bolts holding the tank to the bowl or the gasket that goes in between the tank and the bowl.
Since this is a flushmate style (power flush) toilet it takes a special gasket. Also, it is a little more difficult to remove than most tanks because the large pressure tank inside of the toilet tank blocks the top part of the bolts.