the first issue, I have logged in out system to be fixed in the next update.
for the second issue, change the action of the login form:
action="<?php echo (htmlentities($_SERVER["PHP_SELF"], ENT_QUOTES)); ?>"
to:
action="<?php echo (htmlentities($_SERVER["PHP_SELF"], ENT_QUOTES)); ?><?php echo (isset($_SERVER["QUERY_STRING"]) && $_SERVER["QUERY_STRING"] != ""?"?".htmlentities($_SERVER["QUERY_STRING"], ENT_QUOTES):""); ?>"