I keep getting,

Warning: Permissions group 'guest' should be 'Guest'

I've looked over the AR config and the permissions and everything is capitalized.

Can you show me your Autorank config file and the one of your permissions plugin?

Auto Rank - > http://pastebin.com/dxfVzaxj

Group Manager - > http://pastebin.com/wAeMUjQS

You're using the old config, delete the Autorank folder and let it regenerate.

Well he might just be using the old version of Autorank too. Check if you have the beta version and not the old 1.7 release.
I think Staartvin should set the latest beta as a full release in the BukkitDev project just so the big download button points to that, the name mentioning that it's a beta should be good enough.

Closed due to inactivity, reopen if still occuring!