All you need to do is change <?php tweetmeme(); ?> to <?php echo tweetmeme(); ?> and it should show up just fine.
I ran into the same issue when I first upgraded. Basically you want to fill in the same info you use to ftp to the server, this would include port specification, if required by your host. In other words:
Hostname: yourdomain.com:21 (if port 21 is required
username
password
It should work fine then.
