So this is way after the fact of the original question, but I had a similar issue just recently (Jan 2009) with an ubuntu system and an old Epson Stylus 670. My stylus 670 was recognized and when I attempted to print, the job would go to the spool, but the printer didn't print anything.
I was able to solve the issue by going to localhost:631 as suggested. I selected the printer, and then selected modify printer. I pressed "continue" a couple times and then chose Epson as the make from the drop down and selected continue again. When it came to select the Model, foomatic/stcolor was selected by default. I changed it to gutenprint v5.02 (en) and and then clicked on "modify printer"
Once I made this configuration change, I was able to print with no problem. Hope this helps someone out, and thanks for pointing me in the right direction.