How can I fix my Epson Stylus Office BX300F Printer?

The ink cartridges required changing and I replaced ink with a cheaper version on 3 out of the 4 colours. The display is showing that it does not recognize the ink and suggested replacing them with the recommended brand. I replaced with the recommended brand and now 2 out of the 4 inks are still not recognized. I was told that the inks should not have been mixed when changing cartridges even if one of the cartridges had not finished it would have been better to change all cartridges to the same brand. Is this true and if so how can I resolve this problem?

Jackie
August 2009