I apologize for the lack of response in the last weeks, due to this months sequence of summer courses.
I am taking note of the problems reported in the mailing list. Almost all of them revolve around the Windows port, or the statically linked ECL, and the reason is that in both cases ECL relies on an unstable version of the bytecodes compiler, modified to produce files that can be moved around machines and used when a C compiler is not available.
So the current focus of my work is to fix this, but it is not at all trivial. Hopefully this will lead to a standalone version of ECL which is more usable, but in the mean time some instability can be experienced, as reported here.
Just FYI, today I just uploaded another fix to the bytecodes compiler which makes ECL finally build itself entirely with the bytecodes compiler, install this in the core and solves the problem of bytecodes-compiling functions with non-externalizable constants.