As you can read from my earlier post I had similar problems with still images. I don't see any advantage to LR4.4 so I just went back to 4.3 and everything has been fine. I had to uninstall 4.4 and reboot the computer a bunch of times to get 4.3 working again.
I will just wait for LR 5 and install it with caution on anoyher machine first.