I am having trouble with my Epson SX100 printer. Every so often it will just suddenly say 'ink cartridges not recognised' even though the inks aren't low, the only way to fix this is to put a new ink in which is wasting ink and money.I am using compatible inks.
I use an Epson DX4800 and I'm often told that the cartridges are "not genuine" "not recognised" etc, I just ignore the warnings and carry on printing. Never had to renew the cartridges after the warnings.
I can recommend Jettecs for Epson printers... fully guaranteed and superb quality with a real company behind the name.
I use the T0711/2/3/4's in mine. They work as per originals apart from lasting twice as long. Do a google search ad you'll find them available quite cheaply.
Supermarket "own brands" such as Wilkinsons, Morrisons and Asda appear to Jettecs too.