Why do my old XFree 2.1 Motif applications crash?
You need to install the motifnls package, which provides the XFree-2.1 configuration files needed to allow Motif applications compiled under XFree-2.1 to run under XFree-3.1. Without these files, some Motif applications compiled on other machines (such as Netscape) may crash when attempting to copy or paste from or to a text field, and may also exhibit other problems.