Comment 32 for bug 148985

The workaround I did was to remove cupsys via apt:

$ sudo apt-get remove cupsys

This removes cupsys and it's dependant packages

Then, if you run an update on your package lists:

$ sudo apt-get update

and follow this up with

$ sudo apt-get install

You should have the updated cupsys packages

Alternatively, after removing cupsys with the command line interface, you can use Update Manager to obtain the packages you're missing, including the updated GIMP and loads of other stuff that became updated at 2200 GMT +1 on the UK servers.

Hope this is helpful.