I am running into the same issue - I have 8.5 set up to authenticate through a ticket call to getticket.asp code that decrypts a user name and runs through IIS. Once the ticket is generated a our app that runs SSO calls the .qvw file and automatically performs section access.
However, in 9.0 I cannot get the same server when upgraded to work with IIS and communicate appropriately. Is there a way to do this only by utilizing QVWS and qvsviewclient.asp (or modifying it slightly)?
Also, is there a way to just push a user to AccessPoint instead of a document?