We could use some more info in regards to your AAA profile, MAC-auth profile
You should get your redirect and login to work without MAC auth before you implement it.
Which CPPM version are you using? In 6.1 several of the pre-defined services are gone, and among them this the Mac Caching one. But - in 6.1 just use the service-template for MAC cache authentication and you should be fine.
If 6.0.x then you could try some troubleshooting.
Verify the role your client lands in after the MAC reject appears. This should be the guest-logon role (or equivalent) - this is the AAA default role.
Oh - and scan through your services and make sure you have input the correct SSID in your auth profile. Thats often the reason behind "Failed to classify.."