Digital BW, The Print

My 2400 just started doing something odd. I switch between the MK and the PK quite 
often to print on matte or glossy papers. After printing on a matte paper with the MK, I 
switched to the PK to print on Epson luster, but the 2400 print screen will only give me 
matte paper choices. I have an MIS EZ carbon cart in the yellow slot, but that's never 
caused a problem before.

I tried switching between firewire and USB ports, just to try something. I turned off the 
printer and shut down Photoshop and restarted everything. I've opened up the Epson 
printer utility and confired that it's recognizing a PK cart.

Any idea what's going on here? I'm probably overlooking something really basic.

Cheers,
George Le Masurier