Ok, we had in the older 4.5 (I think) a system set up where a new member was a NEWBIE and they couldn't post links and various other stuff, We upgraded to 4.6.8 and now 4.6.9 and we were getting a lot more first post spammers with links so the upgrade broke this rule (group promotion) setting.
Looking at Group promotions - Our promotion is still there but because of the new badges system all areas were blank so a new member joins as a newbie and automatically as there is nothing to say different in group promotions becomes a member with privileges
I have now added a 2 post badge and put this as a group promotion into the system which is now working again
You may want to look at this chaps