but if you want to use this in 3.3.1 I've got it working with
this plugin by changing line 24 in the "relative-links.php" file of THIS plugin.
$url = mj_get_root(get_settings('siteurl'));
$url = mj_get_root(get_bloginfo('siteurl'));
Again I'm not a pro at this and can not explain why you need both plugins but it works.
Only bug right now is images not quite working but I'll post an update if I find a solution.