Once Anticipated Ridgid R4511 Granite Table Saw Recalled Hot
Now it looks like that joy has come to a halt, although temperately. It seems as though the R4511 table saw doesn't play well with stacked dado sets, which can cause them to be "ejected from the saw". The good news is that you can set up an appointment to get a free on-site repair. You should probably stop using your saw until it is fixed.
Please check to make sure your saw is not one of the ones listed in the recall notice, I do not want to hear any horror stories. See the CPSC recall notice for more information.