ies4linux needs i386 gtk libraries
When you look at the package manager for Fedora 10 x86_64, you will find a long list of libraries. Most are x86_64, but some are i386 only. I assumed that ies4linux needed some i386 libraries that had not been installed. So, I scrolled through the list, and installed every i386 library that corresponded to an already installed x86_64 library. In addition, there were a few developmental libraries which I installed in both the i386 and x86_64 form.
All in all, I would say I installed about tweleve new libraries. I did not pay attention to exactly which ones they were.
After doing that, I was able to get Netscape Navigator to run, and ies4linux to install.
With an x86_64 machine, the i386 libraries are not automatically installed. When you have a compatibility issue, one or more missing i386 libraries may be the problem.
When you have a source code tarball, it usually doesn't matter because gcc has the libraries it needs.
In this case, since I didn't have the source code, my guess was correct. I needed some of the
gtk i386 libraries. I do not have a clue as to which of the many i386 libraries I installed were the critical ones. It is probably the case that not all were needed, and that what I did was overkill.
No matter. It worked.