The WindowMaker-0.51-2 RPM included in newer rawhides will not show the themes/etc. menus that are from directories, or the programs menu that is generated from wmconfig. Running it with wmaker --nocpp will at least allow the programs menu to be generated, so perhaps there are some characters output by wmconfig that confuse it?? I know that at least the themes/icons etc. menus can work w/ WindowMaker 0.51, since I know several people who have it and I used to run a version which I compiled myself, and they all seems to work using the default menu...
WindowMaker config files changed format in the new version - if you are not using the new lisp style menu entries you are on your own :-(