Originalmente inviato da
http://gimp.org/release-notes/gimp-2.3.html
GIMP 2.3 must not be installed in the same prefix as other GIMP 2.x versions. If you want to keep your GIMP 2.2 or GIMP 2.0 installation in parallel to GIMP 2.3, you have to choose a separate installation prefix at compile-time and ensure that you use different library search paths for each version. If you do not set up your environment differently for each version, you will experience conflicts with the libraries and at least one version is likely to fail.