Epson Stylus Photo R200: poor black and white prints

[megamurph]

Hi
I do mostly black and white prints. I used to use an Epson Stylus Colour 680 and had really nice rich blacks from it. I've just swapped it for an Epson Stylus Photo R200 and the blacks are really disapppointing - either purplish or brownish. Does anyone have any suggestions for getting a truer black from it? I'm using a Mac - G4 Powerbook running OS X and Photoshop Elements 3.
Any help would be much appreciated.