Comment 14 for bug 148985

Worked for me (amit_9b's fix)
Please note that you will need to update the deb, to your applicable version (i.e. i386, amd64, etc.)

-- Temporary Fix --

STEP 1: Run
 # dpkg -i --force-overwrite /var/cache/apt/archives/gimp_2.4.0~rc3-1ubuntu5_<b>i386</b>.deb

this will overwrite the conflicting file and then give unmet dependencies error.

STEP 2: Since conflict has already been resolved (forcefully), proceed with normal installation
Run :
  # apt-get -f install