Uh, no?
First of all, the unzipping is working just fine for me. You might want to go to winzip.com and get their latest version if you haven't already.
Secondly, it can't change from a zip because if I did that, it wouldn't download for you, it'd try to play it automatically. And yes, you can get it out of your cache from there, but how many hundreds of the others aren't intelligent enough to do that?
Third, yours was probably just a corrupted download, and since you'd have to go through all of it again anyway (not that you didn't get it pretty qucikly), just re-download it. If enough people do have a problem, I'll look for another format to put it in, tho.
And last, don't post to the CZ, I almost never check here. Send me an email, my addy is all over the CIC.
edited for typo