Make sure to check it is using a driver for that Printer. Snow Leopard installs all of them IF the Printer was connected and online at the time of the upgrade. If not, then it has to be installed from a Download
(choose the top item) or by running the Printer/Optional Installer on the Snow Leopard disk.
After that, let's Reset the printing system and install the Printer again and make sure it is loading the correct driver(s) for it to actually Print.
Go to your Apple Menu and choose System Preferences.
Click on Print & Fax Pref icon.
Hold CONTROL key down on keyboard and click in the white area under the Printer name(s) in the list on the left side. A menu will popup.
Release the CONTROL key and use the cursor to choose Reset printing system...
Let it work and then close the window and restart the Mac.
When the Finder loads, go back to Print & Fax and see if the Printer has been loaded again. If not, click the +Plus sign and add it back in.
Here is Epson's Snow Leopard Support page
for your Printer.