Hi, I had the same thing and contacted Epson, below their support, which I followed. Step 7, I did not understand, but in the printer window (where you get those errors) select printer set up / driver / print using.... Here you can select epson stylus photo rx700 - gutenprint v5.2.3. With the gutenprint v5.2.3 it works for me!
epson support
I do apologize if you are unable to print with your Snow Leopard operating system. The issue is possibly due to an incorrect driver being used by the computer. Please follow the instructions below to re-add the correct driver.
Re-add print queue
1 Turn off the printer.
2 Delete the print queue and remove the printer from Print & Fax by clicking on the minus (-) button under the list of printers. Click OK to confirm the removal.
3 Click on the Apple icon in the upper left corner of Finder and open System Preferences.
4 In the System Preferences window, click on Print & Fax.
Note: Do step number 5 only if this is the only printer currently installed in this computer.
5 Press the CTRL button on the keyboard and click on the white box on the left (where the printers should be listed) and click on RESET Printing System.
6 Turn on the printer. Click the (+) button to enter the Printer Browser window. The system should automatically detect the printer. Click the Add button.
7 If the printer driver for your model is included in Snow Leopard (not downloaded from the Epson website) and the system does not add the printer or if it adds it using the Gutenprint driver, contact Apple for assistance. You may need to reinstall the Epson drivers provided with Snow Leopard.