When Amy leaves the table in disgust, she sets down her glass. In the next shot it's not where she set it down, and continues to move around throughout the scene. Also, her napkin goes from rumpled to flat and back.
When Raj calls for the waiter to bring champagne, the waiter is standing right behind him and starts to walk away. In the next shot the waiter is standing still in a different place, and later walks away from his original starting point.
In one scene where Howard is talking to his mother from the ISS, a yellow hard-shell suitcase can be seen strapped to the wall behind him. Such a suitcase would not be on the space station as any luggage would be carried in lighter, more easily stored cases or bags.