My wife was consistently having issues printing to her Epson Sylus Photo R200 USB printer on Ubuntu 12.04.1 LTS.
Noted the error in the printer properties Printing State:
Stopped - Waiting for printer to become available.
This had been happening for weeks to where she had taken to going to the library to print things before bringing it to my attention. Her computer is basically on all the time, but the printer gets powered off & on as needed, and is shared between two computers.
I found one innocuous resolution reference for a similar issue on Ubuntu 11.x. Wait until both Ubuntu and the printer are fully powered on and booted (post-POST), and then re-/connect the USB cable.
This solved the issue. I have seen numerous references to folks stating that swapping out a new USB cable or changing USB ports "fixes" this issue. It is likely that all these problems are simply due to CUPS (or some Linux printing sub-system) getting locked up on the USB device being not ready, and then never polling again.
FWIW: Her workstation is pretty old -- P4 w/2GB & usually dug ~1GB into swap (not actively swapping). Don't know if that matters in this particular case.
Thought it would be worth reporting as it seems like such a trivial fix for something affecting so many folks.
Is this the only fix or is there another way to fix this issue?