Hello! I've installed Ubuntu 12.04 on a MacBook Pro 6,2. Initially the unity-2d-spread worked fine. However after some recent updates I found that when I click on the icon for a program of which several windows have been opened, I only get one of the windows - the one last opened. I can only see windows opened earlier after closing the later windows. Can anybody help me understand why this happened and fix the problem?

Thank you all!