Close all data entry screens other than the update process.  Check the Master Console to make sure you get them all.

Not sure if this is related but, this morning acct. brought me a SO with an order type of "backorder".  All the original lines were still on the SO, even the ones that had been invoiced already.  This has never happened before, and acct. thinks it is a glitch in the system, but I am thinking it is a user error.

We might of found the reason, I have some scripts prompting the user to change the salesperson on the order and not allowing them to go forward if the SO has a certain salesperson.  Could that be it?

Yes, absolutely.  SO are updated by the posting process, and your script prompt would block the write().

Be sure to filter such scripts on SO / PO to when there is a UI, and / or when oSession.Updating = 0

I understand the reasoning, but lost on the script process/language.  Do you know of a good post that I can read up on to familiarize myself with this scenario?

Throw this at the top of your BOI script, and it should exit the script unless the change is done by someone using the SO Entry screen.  (Elliott posted a scripting guide somewhere, which is a great read for anyone new to Sage 100 scripting).

If oSession.StartProgram <> "SO_SALESORDER_UI" Then

Exit sub

End If