Skype Video Freezes! What should I do?

I am using a Dell N4010, when I chat with my dad, using Video Call, his video and my video freezes, as in it didn't move! But when I go to Dell Webcam Control, my cam is moving, but in skype, it's frozen. Then I realized that everytime I change windows, our videos move a bit but freezes again if I don't change a window. So, what I did, is I keep clicking on the taskbar and the skype window alternatively and continuously so that my dad's video and my video moves. This is very frustating! What should I do? Our internet connection is fine. I've tried to put skype.exe's priority to high through task manager. WHAT SHOULD I DO?!