Just had this message in an RX630. Epson service centre says its a print counter that will block printing eventually. Costs about AUD $90 to get it fixed although there are guides for DYI at your own risk.
The sponges under the print mechanism needs changing at the end of this counter for some reason and has something to do with the print run distance and cleaning of the heads.
Sorry i can't give more info.
Peter Christian, December 2005