I just tried HBOGO as well and I get sound and no video. I went to my xfinity account and I am able to watch HBO content as long as active x is disable and flash enabled. I don't know what the problem is with HBOGO. Looking at the devices listed in HBOGO it seems geared towards ipad's and android devices or maybe it's a problem with windows 8.1. I know that I did not experience any problems with that site when I had my windows 7 tablet.