Not sure if this is a potential bug or my configuration but I couldn't find anything in the recent past pertaining to this issue so I thought I'd share.

I just fired up a Joomla! website, here's my details:
CentOS 6.2 (x64)
PHP 5.3.12
Apache 2.2.15
MySQL 5.5.23
Joomla! 2.5.4
MediaWiki 1.18.3
MediaWiki Login 2.4 0212
AuthJoomla2 2.3 0112
Community Builder 1.8

I have administrator approval enabled for new registrations. The new user just gets single emails...I, as the admin, am getting two identical "Site Name - ACTION REQUIRED! New User Registration Pending Approval" emails sent to me.

Can anyone push me in the right direction or is this a known issue with the versions I'm running?