I spoke too fast!
I just tried on a G5 tower and nothing has changed. If my Epson printer is set as default then it prints OK but salmon issue is still present if it is not the default printer.
Andrew, did you test on an Intel Mac? If it's the case, then the Epson drivers might have been updated for Intel computers only. I won't investigate much further as my available time is running low this week... But next week, I'll redo the test with a MacBook Pro.