I had similar problems and error messages with my epson CX4700 and here's how I solved it. It is risky because it involves installing the latest gutenprint, and IGNORING dependencies. But then again, if you run off a liveCD with a persistent home directory, you can afford to take some risks. Anything goes wrong, just start again (with a backed-up persistent home image).

1) download and install latest ijsgutenprint ( 4.3.99 in my case)
2) download and install latest foomatic-db-gutenprint (4.3.99)
3) download and install latest libgutenprint2 (4.3.99)
4) download and install latest cupsys-driver-gutenprint (4.3.99)
- here it will ask for dependencies libcupsimage2 and libcupsys
- force the install ignoring these dependencies
5) add printer the usual way and select gutenprint as the driver.
6) Test print worked!


What didn't work:
1) if you use the recommend default drivers (gimp-print etc), you get an error message about drivers couldn't be loaded
2) if you use apt, or allow kpackage or synaptic to install the dependencies in step 4) above, CUPS will break, with weird error messages like "client error document format not supported and so on"
3) in general, I find that upgrading major system packages is not a good idea, and often causes something to break.