I would suggest verifying that the database you are accessing is indeed the same from both ID's. (Do this by looking at the Application > Properties dialog - verify that both the server name and the path to the NSF file are the same).
If the server and path are the same, but you do not see the data entered from the other ID, then it could be simply that the view you are accessing is filtering the documents to only show documents created (or "owned", etc) by the current user id. See if you can switch to a different view, or create a custom private view with no selection formula, and see if you now see the documents.
If you still do not see the document, then the database was probably designed to use a reader-names field computed in some way to the current user. That would result in user id "X" not seeing documents created by user id "Y". The only way to "fix" this would be to modify the form design to not use reader-names.