gimp rpm is not built correctly because the gimp.spec file uses configure --prefix=/usrcd, but the rpm builds into /usr thus gimp is unable to load scriptfu or the user_install script because the reside in the /usr tree and not /usrcd, I dunno wtf usrcd is, but the fix I used was to extract the source RPM and then edit the spec file to use configure --prefix=/usr, then invoking rpm -bb /usr/src/redhat/SPECS/gimp.spec which built the package correctly.
this has been fixed in a later gimp package.