Following are the symptoms I have from time-to-time on my 7900 - and I've experienced it on a friend's 4900.
MAC OS X 10.8.3
Epson 7900 MAC Driver 8.68
Using Lightroom 4.4, I'm printing on 24" wide roll paper-and I setup a custom paper length to, say, 32". Sometimes that's exactly what I get and sometimes after changing the paper length to something else, via a new -OR- re-used custom paper size, it comes out wrong and chops the print short or runs out the paper then chops it. In any event, I can't find a reproducible pattern and it wastes expensive media when you're not expecting it......
This despite the fact that it looks exactly correct on Lightroom's Print module screen, e.g. 24" across the top and 32" down the side.
I have been using Borderless (Retain Size); making sure that scaling is 100% or off - whatever it needs to be for the true size. I usually print leaving an extra 1/2" of white on the end about an 1/8" on the running sides. Size width never seems to be a problem.
My usual workflow is to
1. Select/click an existing Template in LR's left control panel (print module) that's close to what I want to do - e.g. 24"w x 32"h.
2. Define a new Custom Paper size (e.g. Manage custom sizes) and setup a new paper such as 24"w by 33" length for example, in [page Setup]
3. Set that as my new Default in the [Paper Size] dialog and click [ok], in [Page Setup]
4. Visit the settings in [Print Settings] to make sure the driver's settings are set the way I want for Roll paper, cutting, color management, etc
5. Check that the display in the Print Module looks 'right'. eg.g. rulers show expected dimensions, etc
6. Click the + in the Print Template and save it as a new Template. Double-check everything again and right-click what I just created and Update With Current Settings.....
6. [Print One] ... and cross my fingers ....
Sometimes it's great - and sometimes the length seems to be the length I just previously used.
Now, I've done some reading where I can and I see suggestions like deleting all the printers and re-installing (ugh, painful) - so I haven't done that.
This week I will try doing two different things ...
1. I will turn Rotate to Fit off in LR's control panel and, instead, rotate the image in Develop so that it is oriented correctly for prints like 24x 32h. So, no auto rotation. will keep the printer in 'Portrait/Vertical' mode.
2. Switch to Roll Paper - Borderless Banner
Has anybody else experienced this or do y'all have a solution ?