Secondary Usergroup Permissions?

[Jaxel]

I have the following permission on one of my mods: "Can moderate comments".

I check this permission in my mod using the following line of code:

$perms['modcomments'] = ($permissions['medialibmodperms'] & $vbulletin->bf_ugp_medialibmodperms['canmodcomm']);

This works fine, if the permission is granted to a primary usergroup. However, I am trying to make a secondary usergroup and give them this permission. However, as a secondary usergroup, they don't appear to be getting this permission. Am I doing something wrong?