One of the libraries in the libglade package, libglade-gnome, is linked against libdb.so.2, which is provided by recent versions of gnome-libs. However, a very old and incompatible version of libdb.so.2 is provided by libc-5.3.12-31, which I have installed on my machine. I then tried to compile an application which uses the libglade-gnome library, and it tried to use the old version of libdb.so.2 (since I didn't have a recent enough gnome-libs) and failed. The gnome-libs dependency in the libglade package needs to indicate a version of gnome-libs that is recent enough that it provides libdb.so.2. A related issue here is that libdb.so.2 does not show up when you run "rpm -q --requires libglade". I don't understand why.
Not _exactly_ sure what the right resolution here is, but I'm inclined to say nothing. The libglade package doesn't require the newer version of gnome-libs, it requires the version it specifies and libdb.so.2. (With the dependency on libdb.so.2 being only because it uses gnome-libs) We shipped libdb.so.2 in a separate package for years; it got moved into gnome-libs for 8.0, since nothing else used it. If you install another package on the system that provides this library, all sorts of things are going to go wrong. There are all sorts of ways one could break a system by installing a package that provides a spurious incorrect library version; don't think there is anything special about this one.