Thank you both for your reply.
Cralor thank you for the URL. That will help me solve my own problems next time
However I don't need to include that function in my own code as it is part of blizzards UI and can be used by any custom addons. The function you posted was enough for me to spot the problem though, which is what Slakah pointed out.
Slakah you are correct, Blizzard must have changed the function since patch 2.4 because I never had to pass that argument in the past... Im not sure if passing self is correct though. I can't remember if self actually passes the reference of the object. I may have to pass the text based name of the XML object, or a reference using getglobal.
I'll use the site Cralor suggested to look at an existing scroll frame in blizzards UI to see what they pass to the function.
Thank you both.
Felankor