I've gotten the final word from Support on this...There is a "bug" with TeamSite 6.7.1 and Windows API that requires any user that will be utilizing preview and generate functionality be added to the Local Security Setting "Log on locally". There is no workaround to this issue at this point, and from my understanding, this is something that a lot of customers are taking exception to. Engineering is working on a workaround, but there is no estimated date for that to be completed yet. They recommend creating a domain group and having that group manage all TeamSite users. Then, add that group to the Security policy.This is currently the only option for users to be able to Preview and Generate.