Thanks. This fix is already in development branch 'fix/64bit'. As it's now possible to have multiple git repositories I've pushed the development tree to repository "dev" too, so it's possible to see what's not yet released.
Bug found. It's actually not in the emulation but the CAOS 3.1 has a single byte error. Will be fixed in the next release. Meanwhile it's possible to fix it in an existing installation by editing the file caos__e0.853 at byte 1c70h. This byte is 00h but should be b7h.