I am now suspecting that it's a package related issue....
does anyone know of any method of asking apt-get to recheck all the packages installed for integrity?
Barney, I get the same error. I ssh into my server from the desktop fine. I can apt-get update and upgrade. However, if I want to edit a file using nano or vi like sudo nano index.htm nano opens fine and I can see the file index.htm. If I then use the cursor keys to move through the file I get Segmentation Fault and get returned to the prompt. There is usually "OB" at the prompt. Funny thing is I can still see the remainder of the file nano opened and have to clear the terminal.
Have you managed to solve the problem? Was it something to do with the software package?