TYPO3 Core

I've got the solution...

The JavaScript from kb_md5fepw is incorrectly.

WRON Function:

function superchallenge_pass(form) {
        var pass = form.pass.value;
        if (pass) {
            var enc_pass = MD5(pass);
            var str = form.user.value+":"+enc_pass+":"+form.challenge.value;
            form.pass.value = MD5(str);
            return true;
        } else {
            return false;
        }
    }

Use the Original JavaScript from the newloginbox and it works fine (attatched)

Resolved, no change required:

Problem in extension, not in core.