PROBLEM: SAP script written on standard Web protocol fails on every OTHER iteration

We have a portal single sign on application that in a basic sense works like this:
1) The first time a user signs on his authentication details are stored in a cookie
2) the user gets access to an sapwebdynpro dynamically generated javascript web page, and enters data
3) after he hits save or submit, and the transaction is accepted, he returns to the same page with a frame at the top that says "data saved sucessfully"
4) On the second iteration, the SAP application looks for the previously stored cookie and if if it the cookie not there the system re-authenticates the user through the single sign on portal rather than the previously generated cookie

If the second iteration fails – why would the third fail, and the fourth pass?

Our hunch is system corruption, as when signing on as the official administrative user the problem goes away. Since I use a different administrative sign on, I potentially have write permissions to the registry (thank you Steve Antonoff of Orasi for this idea) and could have corrupted it.

If it is not system corruption, I had one more idea, what is the ORD in web_reg_save_paran is alternating between two different values? Simple enough problem to solve if this is true. Just check if the iteration number is even ( using MOD 2) and conditionally change the value based on the iteration. This can be easily solved by setting the ORD value in web_reg_save_paran to all, replaying the script, and setting parameter substitution to on, and seeing if the value changes.

Ideas?

Thanks
John