Any word on progress with this? I've been waiting for this so I could do a migration and use CDE as my primary desktop environment, which will also help me identify and fix more issues. :)
Strangely enough, this turned out to be a Motif issue that went away with the latest commits in Tim's fork. This can be closed!
This might be less of a dtwm issue and more of an X11-in-general issue. Can you replicate this with another X11 window manager? e.g. FVWM, EMWM, Metacity, xfwm in XFCE, etc...
Various fixes with Tim Hentenaar's Motif
Update SearchCalls.c
Updating _XmPutScaledImage for newer Motif
Testing jns' preliminary patch
[dtcalc] free(): double free detected in tcache 2