hi edi,
i found this on the hompage from epson, check it out:
Q: Why does my printer print garbage from MS-DOS and Windows?
A: When a printer prints garbage, it usually indicates a faulty cable or a loose connection. Power OFF your printer and computer. Disconnect and reconnect the cable on the printer and computer. Once the cable has been reconnected, power the printer and computer back ON. Try printing from MS-DOS. If you are still getting garbage, change the cable. We recommend getting a fully shielded cable, preferably 6 feet or less in length. If you are still experiencing problems after changing your cable, you may have a computer or printer port issue. If you take the cable and printer to another computer and it works fine, have your computer's port checked by an authorized dealer. If it still gives you garbage from another computer, have the printer taken in to be serviced.
greetz
hugo