file_scan_directory recurses when running sub folder multisites.

This is a bit of an odd one. I followed the directions (http://drupal.org/documentation/install/multi-site) for creating sub folder multisites.

I have drupal 7.14 installed in /var/www/drupal
I then have sites in /var/www/drupal/sites/site_1 and /var/www/drupal/sites/site_2

In sites.php I have:

$sites['site_1.drupal.dev'] = 'site_1'
$sites['site_1.drupal.dev.site_2'] = 'sites_2'

This works fine but when you hit a page that runs file_scan_directory it proceeds to get itself into a recursive loop. Below is a sample of a var_dump of $dir from file_scan_directory

string './/site_2/site_2/site_2/site_2/site_2/site_2/sites/all/modules/custom_formatters/includes' (length=101)
string './/site_2/site_2/site_2/site_2/site_2/site_2/sites/all/modules/custom_formatters/plugins' (length=100)
string './/site_2/site_2/site_2/site_2/site_2/site_2/sites/all/modules/custom_formatters/plugins/export_ui' (length=110)
string './/site_2/site_2/site_2/site_2/site_2/site_2/sites/all/modules/custom_formatters/scripts' (length=100)
string './/site_2/site_2/site_2/site_2/site_2/site_2/sites/all/modules/date' (length=79)
string './/site_2/site_2/site_2/site_2/site_2/site_2/sites/all/modules/date/date_all_day' (length=92)
string './/site_2/site_2/site_2/site_2/site_2/site_2/sites/all/modules/date/date_api' (length=88)
string './/site_2/site_2/site_2/site_2/site_2/site_2/sites/all/modules/date/date_api/images' (length=95)
string './/site_2/site_2/site_2/site_2/site_2/site_2/sites/all/modules/date/date_api/theme' (length=94)

Eventually it just times out and throws the following:

https://skitch.com/digital006/e8git/bcdev.drupal.dev-8080-admin-modules

Is there anyway to stop this?