I have one of those and used to have the same problem. Mine would clog when the women would flush tampons. For some reason they always got hung up. I put an end to that and then replaced the flapper with a Korky flapper with an adjustable water flow. Don't know if they make them anymore. Lowes is where I got mine. The Korky allowed a bit more water in the flush cycle and have not had any problems for several years.