Mike,
First, please understand that I am not OneCare Support, this is a peer forum and I'm just another user, so I don't make policy.
As for why this happens, it's an anomaly of the technical side of the system. Though in most places that aren't currently supported by OneCare you would see a message stating that OneCare isn't available in the location, I see that this list doesn't appear to be complete for all possible combinations of language and location. For example here's a link to the page someone using English in India would see:
http://onecare.live.com/site/en-in/tryscanner.htm
Unfortunately, the way this system works it often created problems for those who originally installed OneCare in a country that was supported and then traveled to one that wasn't. Though this has subsided, I'd guess that loosening the system to allow travel has resulted in holes in the blocking of the trial that you have fallen through.
For example, is your PC set up for US English language or some other that is a supported locale? If so, the trial would allow you to install, since until you attempt to purchase it would have no knowledge where you are really located. That's because the back-end validation is done within the billing system, not the operational system itself.
If this sounds confusing, it is, and it's completely a result of the fact that though theoretically you can access OneCare from anywhere the Internet is available, there are still legal and marketing boundaries that preclude this possibility. The technical effects are more subtle, since they depend more on how well peered a location is when there is no actual supporting infrastructure in that country or region.
OneCareBear
