Well, obviously the problem is not residing with the linker or the installation of gtk; ldconfig doesn't make mistakes. The problem is that pkg-config is acting up. What bothers me a little is that the configure-script is using /usr/bin/pkg-config; on my system, where I installed gtk from sources, it's residing in /usr/local/bin. Is there perhaps a second pkg-config on your system which is configured with the older version information? A second possibility I can think of is that the script is using cached information, so it doesn't go out searching for where the program truly resides. Try a 'which pkg-config' and note the directory it returns. Also, run 'make clean' before attempting to reconfigure gtk.
