Hitbox used to blacklisted for malicious ads by adblockers. Just throwing that out there. I don't know if it's the site that caused problems but it's worth looking at.
...Just tried, can't access it at all right now. A little late for your stream, but maybe you just have bad timing.
Hmm... I use AdBlock+ with Firefox, and I occasionally have issues. When I do, I reluctantly load Chrome. HB does occasionally have problems with some browser and flash pairings. If any of you want to try loading a test stream in the next few days, post here and I will open a generic stream so that you may test your ability to view it, at a time that is mutually feasible.