I was having a problem getting Video on Demand with my FIOS connection. The solution is to disable the DOS button on the Firewall Basic Settings tab. Apparently the router thinks it is being DOS'd when getting Video on Demand. Changing the Firewall to enable to disable did not have any effect on the video.
More information about what is being disabled
DOS Protection When enabled, the router will prevent DOS (Denial of Service) attacks coming from the Internet. DOS attacks are making your router=92s CPU busy so that it cannot provide services to regular traffic. Default is Enable.