This is not a functionality bug, but potentially a performance issue. In course/lib.php's get_module_metadata() function a static variable is initialized to cache module information and the information is stored in it, but cache never gets used because the check to see if module information has been stored is incorrect.

The check current looks like this:

if (isset($modlist[$modname])) {

    // This module is already cached

    $return[$modname] = $modlist[$course->id][$modname];

    continue;

}

It should look like this:

if (isset($modlist[$course->id][$modname])) {

    // This module is already cached

    $return[$modname] = $modlist[$course->id][$modname];

    continue;

}