I can confirm that the same issue exists on the Epson R3000. Custom paper sizes under 10" in height cause the paper to eject without printing. Again, this is with Mac OSX 10.8.1, CS5 and CS6. FYI
Message
Re: Issues with roll feed on 7800 / Mac OSX 10.8.1 / CS5
2012-09-12 by clayharmon47