Everybody check for this:

The username doesn't show up on the welcome page. This was reported to be fixed with release 2.6, but it's still there.

Open invite_friends.tpl and where it says

Code:
<h2>Welcome to {$site_name}, {$username}!</h2>
Change it to

Code:
<h2>Welcome to {$site_name}, {$smarty.session.USERNAME}!</h2>
and as far as my testing goes, the "USERNAME" is case sensitive.