I've just upgraded to Kubuntu 12.04 and having problems installing Gimp 2.8, I was wondering if anyone can help me?

I've followed these instructions:

sudo add-apt-repository ppa:otto-kesselgulasch/gimp
sudo apt-get update
sudo apt-get install gimp

but get this error:

The following packages have unmet dependencies.
gimp : Depends: libwebkitgtk-1.0-0 (>= 1.3.10) but it is not going to be installed
E: Unable to correct problems, you have held broken packages.

I've tried running these and trying again with the same problems:

sudo apt-get clean 
sudo apt-get autoremove 
sudo apt-get update 
sudo apt-get upgrade 
sudo apt-get -f install

also running

sudo apt-get install  libwebkitgtk-1.0-0

gives me this error

The following packages have unmet dependencies.
 libwebkitgtk-1.0-0 : Depends: libgail18 (>= 1.18.0) but it is not going to be installed
E: Unable to correct problems, you have held broken packages.

and then running

sudo apt-get install  libgail18

gives me this error

The following packages have unmet dependencies.
 libgail18 : Depends: libgtk2.0-0 (= 2.24.10-0ubuntu6) but 2.24.10-1oneiric6~ppa is to be installed
E: Unable to correct problems, you have held broken packages.

The bit that caught my attention was but 2.24.10-1oneiric6~ppa is to be installed - but I don't know what to do with this. I've rebooted and the error messages are the same. Can anyone help?

** EDIT ** I've found someone with the same problem, unfortunately the link is in German so I can't completely understand what the solution (last post) is - here's the google translated link : http://translate.google.com/translate?sl=auto&tl=en&js=n&prev=_t&hl=en&ie=UTF-8&layout=2&eotf=1&u=http%3A%2F%2Fwebcache.googleusercontent.com%2Fsearch%3Fq%3Dcache%3A1U2Uat6XqUsJ%3Aforum.ubuntuusers.de%2Ftopic%2Fprobleme-nach-update-fehlerhafte-pakete-aus-on%2F%2B%26cd%3D3%26hl%3Den%26ct%3Dclnk%26gl%3Duk&act=url