When e.g. LC_CTYPE is set in .zshrc with 'export LC_CTYPE=foobar', the variable is not exported. The variable is visible if you type 'typset' at the prompt, but not when you give the command 'export'. The variable is correctly set if declared in an interactive shell, e.g. with 'export LC_CTYPE=foobar' at the prompt. The bug is described at http://va.debian.org/Bugs/db/59/59326.html.
Should be fixed in next rawhide (3.0.7-5) - .zshrc isn't where you are supposed to set variables, though: .zshenv is better suited for that. Thanks.