We have a toilet in a spare bathroom which was added onto the house (converted from a pantry, we suspect) by the previous owners, and not really done very well. In particular, the floor was probably just wood under tile (ie, no vapor barrier), though we haven't de-tiled to verify. However, looking at the toilet's drain lets us see it.
The toilet leaks around the O-Ring about every four to six months; we've replaced it 5 or 6 times since we moved in (3 years ago). We're getting a bit tired of doing that. We suspect it is because we can't get the toilet to sit perfectly still - even with shims, the toilet still moves a small amount over time.
Short of replacing the floor, which we could do but would obviously be a rather large and expensive project, is there a better solution that will last longer? We likely will replace the floor within about 2-3 years, but at the moment would prefer to put that off if there is a good solution (we have a couple of toddlers who are potty trained/potty training and losing access to the first floor bathroom for weeks would put a crimp in that).
I did see this question, and wonder if that is a possible solution. How could I tell if the height of the flange is the problem?
Edit: My toilet is an American Standard Cadet 3, with the elongated bowl; here are the installation instructions. It doesn't seem to require any particular height of the flange from the floor (which makes sense when I see the picture). The bolts themselves are plenty high, I can screw them down with no problem.