For NBC during the last Olympics, I found you had to allow third party cookies, FLASH, and not have delete browsing history on close. Hope one of those is your problem and helps you.
It appears you need patience on this site. I tried the link and initially it didn't work. 2 tires with no success. I checked the help menu and didn't find anything relevant to the problem. After several minutes I noticed that Verizon FiOS was showing up top. Went back to the program and it worked.
Make sure cookies are enabled and you have the latest version of flash as they could also cause problems.