evince won't install

Thank you for your bug. Can you run "apt-cache policy evince" an copy that to a comment? When happens if you try to "sudo apt-get install libpoppler1-glib"?

apt-cache policy evince gives:-
evince:
  Installed: (none)
  Candidate: 0.8.1-0ubuntu1
  Version table:
     0.8.1-0ubuntu1 0
        500 http://archive.ubuntu.com feisty/main Packages
        100 /var/lib/dpkg/status

sudo apt-get install libpoppler1-glib gives

Reading package lists... Done
Building dependency tree
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.

Since you only requested a single operation it is extremely likely that
the package is simply not installable and a bug report against
that package should be filed.
The following information may help to resolve the situation:

The following packages have unmet dependencies.
  libpoppler1-glib: Depends: libpoppler1 (= 0.5.4-0ubuntu8) but 0.5.4-6 is to be installed
E: Broken packages

what about "apt-cache policy libpoppler1"?

apt-cache policy libpoppler1 gives

libpoppler1:
  Installed: 0.5.4-6
  Candidate: 0.5.4-6
  Version table:
 *** 0.5.4-6 0
        500 http://www.claws-mail.org ubuntu/amd64/ Packages
        100 /var/lib/dpkg/status
     0.5.4-0ubuntu8 0
        500 http://archive.ubuntu.com feisty/main Packages

you are using non official sources which are creating the issue, closing that's not an Ubuntu bug

What non official sources are you referring to?

" 500 http://www.claws-mail.org ubuntu/amd64/ Packages"

OK. But is this because 0.5.4-6 is incompatible with evince (i.e. evince doesn't work with it) or is it just that something in the packaging system is checking for 0.5.4-0ubuntu8 specifically?

If it's the latter I would consider that a bug.

That's because you need to have the libpoppler and it's binding in a matching version and it looks like your extra source provide buggy packages, you should not use non-official packages like that, it's likely to break the upgrade to gutsy because we work on the Ubuntu upgrades and don't test some random versions distributed elsewhere on internet

But that presumably means I can't use Claws-mail, which is a fork of and is superior to the Ubuntu-provided Sylpheed.

Or is there a way of getting Claws to sit happily with everything else?

You can install sylpheed-claws on feisty. claws-mail is available on gutsy, maybe you can open a request for an official backport https://bugs.launchpad.net/feisty-backports/+filebug

OK. Thanks for your help