Please see the following information for display resolutions:
Also, you can see the native resolution for your Samsung SyncMaster here:
Thanks for responding.
I had already been through the Display Resolutions Frequently Asked Questions (FAQ), and many other resources, before I posted my question.
This is not an instance of a user that doesn't know how to set a machine up or customise it. The system is clearly malfunctioning; I am looking for someone that has seen this particular malfunction before and knows how to fix it.
In this case, please wait for another user with similar problems who can share with you how the issue was solved.