Question: I'm using EJB3 and I have a problem related to refreshing my `EntityManager`. 

The problem is that my apllication must be prepared for use by many people but if one person updates the same date, the `EntityManager` is not bloking that row and it doesn't see the changes other people do after x minutes. 

Does anybody know how to refresh an `EntityManager` when I do a 'select', 'insert', 'update' or 'delete'?

Answer: 
The only change I'm seeing is simply caused by the browser hidiing / showing its vertical scrollbar, thereby altering the body width slightly and causing the centered content to readjust.
Your image is taller than your window browser, so, your browser have to construct a vertical scrollbar. This is why, your body width is affected.