Epson 9890 + 7880 unreliable on new MacPro. HELP!

Hardware:

Epson 9890 (on LAN via gigabit switch)

Epson 7880 (was on the same switch, now unplugged)

2013 MacPro

using Photoshop CS4 and CS6

We had the 9890 and a 7880 hooked up via USB and both were printing ok. We networked them via a gigabit switch, and both were ok for a few prints. The 9890 then printed a blank page, which it then cut to the right size but didn't print. And again..

I then printed on the 7880, and after a few prints the same thing happened on the 7880.

I reset the printing system on the Mac (erased all printers) and reinstalled them. I now only have the 9890 installed and plugged into the switch, and it printed a few prints fine, then a blank again.

Having reset the printing system again, the 9890 was running smotthly for a day. It had a day of no use, and then thismorning I tried to print and it did something else. I tried to print a stip 24x4" with 2 6x4's on it. It printed 1 piece of 1 of the images about 1x4" on the page. That was it.

Could it be OSX Mavericks? Photoshop? Anyone have this/something similar happen? I have networked a few large format Epson's before and no trouble between them. All software (drivers and Mac) are up to date.

Help greatly appreciated!!

Andy