I'd second that... either a bad profile, or you're sending the print incorrectly to use the profile you have.
Try running a totally different paper, like Premium Luster. Make sure you're assigning the paper profile in Photoshop, and turning the Epson Color Controls off.
Another thing I do all the time is to print a step wedge... That lets you see exactly what the printer is dong to every value from 0-255, and if there's something weird happening you can see it.
I made one up, it's here:
http://www.teddillard.com/graphics/step.jpgThere's also a vid I posted on the YouTube showing correct color management procedures sending to the printer in OSX:
http://www.youtube.com/watch?v=nlccFMPZxQs The one fairly remote possibility is that the heads need cleaning... try that too.