Market - missing apps

[Griever]

UPDATE!!!!

Contacted HTC.
They more or less told me that the reason apps are missing from the market is due to the apps being incompatible with the current ROM I am running.

Contacted Developers:
They said it was kinda true, but are certain its because the ROM isn't approved by Google therefore can't access encrypted Apps and made reference to previous happenings with other new release ROMS should sort itself in a week or two.

 

[thisnameistaken]

I've noticed there are apps my mate can download (Hero on Orange) that I can't find on the market (Hero on 3). Google's April Fools Day app didn't appear for me, and I tried looking for Neo Music the other day and couldn't get that either.

Is my provider killing off certain apps in the market?