I've downloaded your official libs for JavaScript, ActionScript, and PHP but can't open any of them with either Windows XP built-in zip file support or Winzip.  Both say they are not valid zip archives, and are either corrupted or invalid.  What's up with that?

I had the same problems!

It turns that that you get a problem file with IE. I used Firefox (by chance) and I got a very valid zip file!

(Still can't explain why, but who cares maybe!)

You can also use a different Zip utility (other than the default on windows) - Like Stuffit, WinZip, etc.  I had the same issue.  I opened the same file with Stuffit and it worked fine.  Let's just say I had a lot more difficult of a time trying to reset the zip utility back to default. :D