AFP Out Of Date In OS X Lion

Im very new to these forums so hi. Im running the latest build of lion dev on my imac, and made the error of not checking full compatibility before installing. My problem is that all my itunes media and plex 1080p content is stored on the readynas NV+. Iv found that movies of 720p and above wont play smoothly (Cifs) due to the poor speeds i am experiencing. I have done all the above which allows me to connect as a guest only to AFP but not as a user. This is not allowing to point itunes through AFP and when i do it just hangs. Iv managed to use plex as a guest connection and from a 30 min 1080p movie clip it played fine. What im looking for is a solution to get this readynas NV+ to play nice with itunes and lion or im gonna have to sell. Im quite a novice when it comes to this but am competent enough to follow any instructions you guys can help me with. Please help, all i want is to get all this to work as i imagined and not feel like i have spend a load of money and getting no results.