I also have had no problems getting the 150 per day. Sometimes you may hit it just right and get Roberts first message. It can mean the videos are restarting a cycle and you hit that downtime.
Also if you try to get a video faster then normal that message can show up. If you get the first message, just try again and it will probably work. I run multiple instances of different ways to get those vids and have not had a problem in awhile.
Other then the fact I believe that WGT did something during their last update that makes NOX no longer being able to connect to the site.
Also a good way to know whether you have reached the limit, add 150 to what you started with. When you reach that number you are done, for the day.