Since upgrading to 12.04 I have been unable to print. The Printer is recognised and access is available to the SD card plugged into it. Print jobs keep queuing up. In System Tools > System Settings > Printers, The printer appears and the details are:
Ready "ON" / Location "-" / Model "Epson Stylus Photo RX620" / Supply Level [blank] / Jobs 10 Active "SHOW" / Default (ticked).
Print test page simply adds a job to the list produced when "SHOW" button is pressed. On that jobs list, "Job State" in every case is "Stopped". When a job is highlighted, the options to Pause and Resume Printing are not clickable, while that to Cancel Print Job is clickable, but has no effect.
When printing from a programme, A "Printing" warning pop-up appears on screen, But soon disappears. A job has simply been added to the job list: there is no activity at the printer whatsoever.
I use the traditional Gnome desktop, although this problem is not desktop-dependent.