I have (2) toilets in my RV that are both the SeaLand Model 210 by Dometic. One of these toilets leaks when you sit too close to the front of the seat. The leak is at the base of the unit. I have replaced the seal, tightened both the mounting bolts and the rear wood screws to no avail. It continues to leak, but only when you lean forward in "the thinking position" which is pretty much standard for us guys. I am at my wits end with the toilet, it appears to be very stable, there are no cracks (visible) that I can see, yet the leak continues. Any suggestions or help would be appreciated.