Tried to download the "Galileo" sequence and the thing simply hung up on one of the frames. I watched it try to load the same frame about 50 times and get 30% done before I gave up.
I did get some of the other features to work...
I'm sorry to hear that you're having troubles. Specifically regarding that Galileo animation, however, I was able to download it okay although it took about a half hour with my DSL connection. I'm wondering if possibly some firewall issues that you mentioned before may be causing you trouble? I was worried that my system requirements weren't sufficient, but my 2.4 ghz Pentium with 2 gigs of RAM doesn't miss a beat with it so far....it runs perfectly. The only situation with WorldWind and myself has been the learning curve, which is there, although far below that of something like Photoshop :-)
I've found that it's most helpful to set a goal or destination in mind and load the best mapset for that goal. It's a little more difficult to do full-scale touring thoroughout the entire program because some mapsets aren't necessarily very well suited for all geographic areas. If, however, you can get a feel of what sorts of maps give you the kind of information you're looking for, you will probably have a much more streamlined experience; assuming, of course, that your firewall isn't being obstinate :-)
Please also don't underestimate the value of the forums. From what I've seen, they actually have extremely knowledgeable people there who are pleased to give courteous help....an amazing thing in the software arena :-)
Good luck to you and I hope that the program will prove to be a worthwhile install for you.