Is this normal behavior? When I play one of the videos, I hear the sound but don't see the picture unless I expand to full screen, in which case I can't view other resources while I watch:

This isn't just the Morris videos but all the courses I've tested.
My computer:
HP Pavilion dv7 Notebook PC 64-bit Intel® Core i7-2670QM 2.20 GHz Windows 7 Home Premium