A DLL conflict is the first thing that occurred to me.  I tried
exiting Firefox and Thunderbird, the two applications that make
use of LIBCxxx, but the behavior of Lucide was the same.  My
previous experience with DLL conflicts suggests that such a
conflict prevents the app from running at all, whereas Lucide
launches just fine, but crashes when the Open Document button
is clicked.  Could the Open Document dialog be causing the
loading of a DLL, or a routine from a DLL, that is causing the
problem?  Recall that if the desired document is entered on a
command line, Lucide will launch and load that document.  Avoiding
the use of the Open Document button makes it work.

Both systems run an ancient version of Thunderbird that uses
LIBC05.  One difference is that my office computer also runs
(usually) an ancient version of Firefox that also uses LIBC05;
Firefox and Thunderbird happily coexist without resorting to
LIBPATHSTRICT, whereas my home computer runs Firefox 10, which
needs LIBPATHSTRICT to coexist with Thunderbird.  But Lucide
runs fine on that system.

Very puzzling.