Hi,
Today we pushed a change that allows premium Google Analytics accounts to access up to 50 custom variables through the Core Reporting API.
So if you have a premium account, and track data to custom variable 43, you may now use the dimension ga:customVarValue43.
Also keep in mind that standard accounts can still only access up to 5 custom variables.
Thanks,
-Nick
btw, if you haven't migrated from version 2.3 to v3.0 or v2.4 or both Management and Core Reporting APIs, you will need to do so very soon. If you haven't yet, we've created a
simple migration guide to help you out.