I believe this is an issue with your logon token expiring.
How are you creating the X-SAP-LogonToken?
- /logon/long
- /logon/token (if so, is it a token or serialized session)
- /logon/adsso
If Raylight is used for getting prompt info, are you also using the Java rebean SDK or OpenDocument?
Did this work prior to SP06?
How many minutes, roughly, from when you log on, to when you get the error?
Dan