Thanks for confirming you have the same issue. From reading more and more threads that are appearing at the android market forums - my source as asked for is...
Technical Help - Android Market Help
it seems that this problem is indeed related to Google's new anti-piracy strategy. Basically if your using a dev phone, an unlocked phone or one from a carrier who is not part of the open handset alliance then you cannot get at 'copy protected' apps.
Apparently this covers most paid apps and some free ones. That explains why some paid apps can be seen.
The only two ways around this that I can see are
1) for Google to remove this policy - which seems to be demanded at the above forums, or
2) for Orange to join the OHA - HTC are alteady members so it's not their fault. Vodafone and T-Mobile are listed as members which is why Wahwah's friend doesn't have the same problem.
The petitions for Google to change their policy can be found in a thread at the above forum.
For me it's not that big a deal, or at least not until a paid app comes along that I *REALLY* want. At the moment it's more of an annoyance.
I've not contacted Orange yet as I was waiting for a few replies to make sure I wasn't the only one with the problem. I'm not sure how to go about doing so, as you said Wahwah, I would imagine that a lot of the support staff won't be able to understand/help - it would take someone at a senior level in the company to get them to join the OHA.
Hopefully if Orange release more Google phones as they have stated, then they will join the OHA at some point.
Anyway, I'll do some more research then fire off an email to see what can be done.