It's hard to tell, so if you could pack your grails-app, put somewhere, and provide a link ( through forum or PM ), then I could check it for you.
I reviewed your files and couple of things you could improve.
1. Put 3 classes created by Acegi plugin into package 'gameaddict' or 'security' or even 'gameaddict.security' ( yours grail app ) so you wont have problems with finding them later. You can use a command like
2. to get info in controller about current user, add authenticateSerive and then use userDomain() method. eg.
I hope it helps