I seem to be having the same problem in Slackware 10.2, which comes with cups-1.1.23 and gimp-print-4.2.7. I also am trying to use an Epson Stylus Color 880.
I started cupsd manually, because it is not enabled at startup in Slackware default install:
, I found my printer device:
A line returned by this was "direct usb://EPSON/Stylus%20COLOR%20880", which I add as a printer:
lpadmin -p Epson -E -v usb://EPSON/Stylus%20COLOR%20880 -m stcolor.ppd
Finally, I tried printing with this command from http://www.linuxprinting.org/cups-doc.html
lp -d Epson -o PageSize=Letter /etc/motd
So, it looks like the print job is submitted. Looking at http://localhost:631/admin
all print jobs I've attempted are listed as completed, but nothing comes out of the printer. Also, I find no errors listed in /var/log/cups/error_log
So, everything looks ok, but nothing comes out of the printer.