I AM trying to help you with some very pertinent questions based on my experience!
When I said the problem is in the file, I should have stated that differently. I feel the problem is occuring before the file reaches the printer. I still do not think it is the printer mechanics since the lines occur in different orientations on the page.
You didn't answer all the questions from my previous post.
What application are you printing from? Photoshop? Elements?
Do you have a PPC Mac or Intel Mac?
Have you tried uninstalling and reinstalling the printer driver?
Did you know that Epson has an updated driver for PPC Mac dated 12-06? Since this is the latest and greatest, I would do this first. If your current driver is corrupted this will take care of that problem.
Epson has had problems with Mac drivers before.
If you want to work with me, I will give you all the help I can, but I need answers.
If you don't understand the question, just ask.