slabbi ...
I was having problems getting uddeim going in J!1.5. Turns out none of the uddeim_config.php vars were in scope in any of the front end functions.
I had to modify the savesettings() function in admin.uddeim.php to 'global' all the variables ...
$cf="<?php\n";
$cf.="global \$config_version;\n";
$cf.="global \$ReadMessagesLivespan;\n";
$cf.="global \$UnreadMessagesLivespan;\n";
etc etc., before actually setting the values.
It now works quite happily in J!1.5 with legacy mode.
I don't know if this is a J!1.5 thing, or a PHP version thing.
-- hugh