I just had a toilet installed in my basement...I SET THE STOOL....it worked fine for about a month and then just started leaking! Not just a little leak but a lot! I've pulled it twice and put new rings...even put a double on but to no avail....it's still leaking. FYI the flange is agout 1/2 inch above the floor so I've had to level the stool with shims...could this be my problem?
If there is no tight seal, then it will leak. Yikes, I pity you. I replaced my toilet just a couple of months ago. Maybe your shims are too high? maybe you can get someone to hold the toilet and look underneath while seating and make sure its forming a tight seal. Are you sure the toilet is not getting rocked back and forth and hence the seal is coming off?