We recently moved into a relatively new home (built in 2004) that has three toilets, and at any given time one or more of them does not flush properly. They all do the same thing: bowl fills up and drains slowly, solids won't flush. Plunging doesn't seem to do much, neither did having the septic tank pumped out, and we have no other problems with the house. We called a plumber who came out and said the problem was that the toilets were really low quality, and replacing them would do the trick. Does that sound like a likely cause? If not, any ideas on what the problem could be that affects all of our toilets?