Problem: Registering members go into two groups

[Sawa Dee SohL]

I have it currently set so when members register their name, they receive 85 Reputation - which puts them into the usergroup ' Regular' - Via promotion.

I still have SOME members, random ones(?) - who register into the Default group ' Members ' - But still continue the same title and Reputation as ' Regular '

It's not an issue that shows on the site, but it shows in the ACP Members : 9 Regulars : 11 - So it's different, and it keeps going, some into Regulars, and some into Members.

Can anyone tell me why it's being seperated into two groups? Should I remove 'Members' in total?

I accidentally removed Super Moderator's, and don't know how to make another one, so I'm scared to do it again.