Oh, there's a trick to that that I haven't tried yet because I stopped watching it on there; I couldn't take the audio delay anymore. I just watch it on sina.com.cn or tu.tv.
Anyway you can try the methods:
1) Let the video load in its entirety in a different browser from the one you normally use. So if you use FF load it on IE or vice versa. Once the video is loaded entirely, go to file and "work offline".
or
2) Go to Start Menu > All Programs > Accessories > Command Prompt
Then type ipconfig /renew and refresh window.