In some scenarios, earlier versions of Outlook clients display errors when you save an item. The errors resemble the following:
However, under those same conditions, Outlook 2010 does not generate conflict errors.
How to disable the new Outlook 2010 automatic conflict resolution behaviorImportant This article contains information about how to modify the registry. Make sure that you back up the registry before you modify it. Make sure that you know how to restore the registry if a problem occurs. For more information about how to back up, restore, and modify the registry, click the following article number to view the article in the Microsoft Knowledge Base:
Article ID: 2755373 - Last Review: Oct 1, 2012 - Revision: 1