Same problem here also got a 560ti. Didn't have the problem before the latest drivers.
Yep. The same thing happens to me. And I also have a Gigabyte 560TI, 2500K, 4GB ValueRam. No overclock around. Maybe is something with nvidia's latest drivers. I'll disable hardware acceleration and see what happens.
Maybe someone else will read this post having the same problem. Disabling hardware acceleration on flash streaming videos WORKS (it worked for me ). Simply RightClick on video -> settings -> uncheck "Enable Hardware Acceleration". It must be something with videodrivers. Goodluck!