Epson 1400 won't print greyscake

Ok... so this one has got me completely stumped and any advice you all might have would be much appreciated!

I have an Epson 1400 and I am running Photoshop CS4, recently our studio got a brand new imac, which is what I am trying to print transparencies on.

I am going through and selecting all of the print settings that I normally do with my Macbook and get really good quality, black transparencies, like "ultra photo premium photo glossy paper", "greyscale", and "quality instead of speed" but ALL of my films come out looking magenta. I can't get it to print in greyscale for the life of me.

What is really frustrating is that it works on my personal laptop, and the PC laptop of a friend, but not our brand new nice imac...

Any thoughts? I am thinking it is just some stupid setting, but I have spent about four hours playing with settings and can't seem to get anything to change what comes out... it all looks magenta.

Thanks,

Michelle
Articulate Ink