i launced xterm, gained root and typed apt-get install --reinstall mp-fremantle-generic-pr as instructed, it said

Reading package lists... Done
Building dependency tree
Reading state information... Done
Package mp-fremantle-generic-pr is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source
E: Package mp-fremantle-generic-pr has no installation candidate

Nobody can help poor little paulie?

Please check your sources list at /etc/apt/sources.list.d/hildon-application-manager.list . did you apt-get update to refresh the package-list. If unsure post your list here to check.

You may not be running the -generic firmware. Since you are in the UK the right package may be mp-fremantle-203-pr, but in any case you can find out with "apt-cache search mp-fremantle".