老式C stumper——大多数键盘输入被古老的XWindows/Motif应用程序忽略

I'm reviving a source build of an old Xt/Motif application that hasn't been worked on in years, and last built successfully on 32bit Red Hat 4. I have it mostly building and running on 64-bit Red Hat 5. There's just one significant problem with the application...it doesn't respond to most of the keyboard input that it's supposed to. None of the menu accelerators work, nor do many of the other modified and unmodified keypresses that are supposed to support specific functions. The only keystrokes the app recognizes are entry into text entry fields and arrow key navigation across widgets with rows/colums of data.I'm reviving a source build of an old Xt/Motif