For all the wonderfulness of HD its still a relative newcomer and we must expect problems for a long time to come. Including problems caused by a fix somewhere else. The standard "we are aware of the problem" and 'it will be fixed in the next software/firmware update' bug me to no end sometimes. But such things go hand in hand with anything remotely related to computers and companies never give a firm date when they will be released.
TNT-HD showing the same movie normally then later stretched smacks of someone trying to save money... not necessarily by TNT. And if E* is doing it TNT should be complaining because in the end it affects them the most. I would.