On Monday 23 April 2012 20:21:40 Greg Madden wrote:
> I would trim your sources list, do you need 'deb-src' entries ? You also
> have two security entries, i use the ~sqeeze/updates one. �Sometimes a when
> a sources entry fails to connect you can get missing packages/depends.

Thanks!  I'll certainly comment out the src lines - as you say, I do not 
really need them, and can uncomment them if I ever do..

But the two squeeze updates are not in fact the same thing.
deb http://security.debian.org/ squeeze/updates main
is, as it says, security, so is necessary.

deb http://mirror.ox.ac.uk/debian/ squeeze-updates main
is not security - there is no mention of security. It is the replacement for 
volatile.

Still, I could certainly comment both out temporarily.

I am still baffled as to why the same procedure worked a week or two ago and 
doesn't work now!!!

Anyway, now to try your suggestions.  Thanks for them.

Lisi