Hi Graham Paull,

I had uninstalled and installed the unique plugin for MOODLE2.8+. Installation went successful. I had done all the needful configurations as in the plugin documentation, but I could see the same as before :: users can lo-gin by multiple attempts.

I am using "Email-based self-registration with admin confirmation" authentication. 

Could you help me with your suggestions.

Many Thanks

Lavanya Manne