Are you using a 2.4Ghz ActivHub? The black USB ones? If so, does it show a green light when you plug it into your computer? Have a look at our Knowledge Base and the article on how to upgrade your Hub firmware if the light is coming on and lit green. If you are not getting a light on your hub, then it may be faulty.
I have created a case reference for you under 00459738 if you want to call in and talk to someone.