I've little doubt that there are third-party ink fillers who don't care if the ink damages the printer. The APC article I mentioned had a picture, IIRC, of just such a damaged Epson print-head. However, some ink-fillers objected saying that they run extensive tests to make sure their ink doesn't damage the printer.
So who to believe? :-) Well, that's the UD of the FUD.
Wade.