I too am having problems with SSO from the portal to backend systems and have read through the SSO and web filter documentation and installed the SSO par file to the portal. However my scenario is slightly different.
I have a web server for the portal that is in it's own domain. The portal app server and backend systems are in a separate domain. The issue I am trying to resolve is to get SSO to work from the portal to a backend SAP CRM system. Web Filter won't work since the CRM system is not running a dedicated web server rather it is simply the SAP WAS.
So the infrastructure is as follows:
1. portal web server www.domain1.com
2. portal app server xxx.domain2.com
3. crm WAS server xyz.domain2.com:8000
SSO breaks between the portal and the CRM system because the SAPLogon ticket is generated by the web server (domain1.com) and cannot be issued to domain2.com.
I don't want to put a dedicated web server for CRM in domain2.com. Since the backend system(s) in domain2 are SAP systems there must be some facility to make this work.
How have others dealt with this scenario?