Got a new one about two years ago, looks great but about a year ago noticed that the beige tile around the base was discolored (bluish), apparently from leakage (I had popped one of those blue-dye sanitary pucks into the tank, so that was tell-tale). My apartment super insists there is no leak, but I think he's wrong. Anyway, I need to replace the tile and don't want a reoccurrence. Is the problem with the wax ring? Could it be an installation problem? (I have a 10" rough-in and contracter installed using the adjustable Toto rough-in to make it fit). A defect with the toilet? Or something else?