Calling DataServiceContext.UpdateObject multiple times on the same object before saving

What happens if you call the DataServiceContext.UpdateObject method on an object, update that object (say, change a property), call the DataServiceContext.UpdateObject method on it again and f开发者_运维百科inally save?

I recently tracked a weird bug and it looks like that was the culprit although I still don't understand what it was actually doing. The save would fail and retrying was performing another UpdateObject (usually with slightly different data). Is there a way to "clear" any previous updates that have occurred before a save?