Problems with an Epson 1000 ICS printer

I have an Epson 1000ICS printer. Ever since I also connected a Dell 540 photo printer to my computer, the Epson printer has not worked properly. I have completely uninstalled the Dell printer and its drivers. I have also uninstalled and reinstalled my Epson printer and its drivers, but nothing helps. It will begin to print a document, hesitate, then sometimes print more. Almost always, an error message comes up saying "Document failed to print." Sometimes it will continue to print after that, sometimes it won't. I have tried cleaning the print heads and realigning them but it doesn't help. What do you think is wrong and what should I do? Thanks in advance to anyone who offers help.