I posted on the MW rotting seal post about my situation. Fortunately our house was still under the builders warranty when we had our MW problems.
The MW tech told me today that I should check the silicone seal at least once a year to make sure it is still intact and that after 10 years or so I may need to have silicone added to insure the seal.
I looked at my MW warranty and it only applies to the original home owner. Are you the original owners? The warranty is very limited and of course benefits MW over the consumer.