This is an old problem, but I just purchased a CIS and so am revisiting it. This has been troubling me for a _very_ long time, and I'm hoping that someone here is wise enough to help me solve this agonising (for me) problem.
I have an Epson 2100 (2200 in North America) which I purchased specifically to use roll paper and print long panoramas. I bought this printer soon after it came out, by the way.
I prepared a pano (in Photoshop CS1) that was 14196x3549 pixels at 273 dpi which measures out at 52"x13" (the roll paper I have is 13" wide, and I wanted to have the max possible sized print). I created a custom paper size which fit the pano.
I used my typical colour settings: I set Photoshop to determine the colours, and used the appropriate Epson printer profile (and then set "no color adjustment" in the Epson driver).
The problems came when I tried to actually print the image. What would come out of the printer would be only portions of the image printed on the the full custom paper size (for example, if memory serves, the image would start far down the paper, and would be shifted up 15cm or so). This is not a cropping issue, the image was shifted hugely on the paper (fyi: the very same image, printed at 20% of the original size, printed with no problems).
I used up two sets of carts and metres of paper trying to get this to work. Lots of calls to Epson tech support, and I finally got a tech to state that there was a limit to how long of a print the Epson drivers would produce (I seem to remember that it's 44"). I tried a few more solutions, but finally gave up in extreme frustration.
I've since read, here and many other places, that the 2100 on a Mac using Photoshop CS2 (which I am now using) _should_ be able to print over 44". I even spoke to an Epson tech at a recent photo conference (Focus on Imaging, here in the UK) who reiterated that there should be no problem.
I was all ready to get back into trying again when a friend who had recently bought a used Epson 4000 wrote me to ask about this strange behaviour he was getting when trying to print long panos...same problem I had been having (at least he saved me from even more hours of extreme frustration).
Panoramas have long been a passion of mine. I bracket shots using a pano head, I then tone map them and stitch them together. I've been stitching panos since I was a beta-tester for the original QTVR software from Apple, looong ago! I am desperate to start printing these, I sure hope somebody here can help me out!