No OS X 10.5 drivers are available from Epson.com for the Stylus Color 860 which is what the OP was asking about. I have wrestled with this issue for quite some time - particularly the lack of a Printer Utility for this printer - but these open source solutions are a somewhat helpful solution.
BQ
There are open source drivers available. Gimp-print and usbtb.
See:
http://sourceforge.net/projects/gimp-print/
and
http://buymelunch.org/printing/usbtb/
The gimp-print/gutenprint packages include a terminal script that allows you to do the Printer Utilities checks via the...