A bug introduced in the 2.5 locale libraries make strcoll() return bogus values when confronted with empty strings. This bogus empty string comparison makes that strcoll no longer defines a strict order on strings, that confuses the hell out of qsort which promptly crashes.
Workaround: set LC_COLLATE to "C"
(Note that xview applications will usually reset LC_COLLATE to LC_ALL, so in cmdtool/shelltool windows, LC_COLLATE needs to be set again.)