I'm not sure which version of Motif is 2.3.1, but that bug sounds like #1412 which was fixed in Motif in June 2009. I use Motif 2.2.3 (which is ok), but I think the current svn sources from motifzone are also ok (version 2.3.2, but they forgot to update the version number so it prints as 2.3.0). I think planetccrma has the latest version.