I thought that the Assets in CiaB were all MOV to be X-platform, but maybe I just have not paid close attention.
Which of the Asset files are you having an issue with? Could be as simple as just installing a required CODEC onto your machine. Adobe tries to make those files as totally benign, as is possible, so that very few users will have any issue. They shoot to be totally universal and fully X-platform.
If you are not sure about the specs. of the files in question, QT Pro (upgrade/unlock) will give you those, as will the utility MediaInfo (ported for Mac, or for PC).
Make sure that you have QuickTime 7 installed. You can install it from the Apple website or the Snow Leopard installation disc, but it is no longer a default part of the Mac OSX installation, since Apple introduced the nearly useless QuickTime X (which isn't the same kind of software, despite the name).