ActivEdit fails to define environment variables to the global scope when register_globals = off in php.ini.
Change:
global $HTTP_USER_AGENT, $REMOTE_ADDR, $PHP_SELF, $generatedContent, $ae_stockbtns, $ae_num;
to:
$HTTP_USER_AGENT = $_ENV["HTTP_USER_AGENT"];
$REMOTE_ADDR = $_ENV["REMOTE_ADDR"];
$PHP_SELF = $_ENV["PHP_SELF"];
global $HTTP_USER_AGENT, $REMOTE_ADDR, $PHP_SELF, $generatedContent, $ae_stockbtns, $ae_num;
at line 82 of Activedit.inc.