As you may know, "Creative Suite CS5" is a version, not a product. Within any given CS version, you can buy 4 different suites that bundle various point products, and you can purchase the point products separately.
As for why certain suites or point products unlock only a limited set of codecs, that decision hinges on the fact that Adobe has to pay a third party for some codecs, such as MPEG2. So the management team for each point product has to decide whether enough users of that product will want all the codecs to warrant paying that fee for each and every license. Let's say the royalty fee for a codec is $1 per license but Acrobat estimates that only 1% of its users will take advantage of that additional codec. In that case, Adobe would pay $100 in royalties for every 100 licenses sold, and only 1 customer would really benefit.
Re: the WMV mystery, let us know if you think of any differences in how the clips were created or if you post some for us to investigate. Until then, there's no way for us to help you.
