What is your source footage?

Agreed I learned a long time ago if it's being run from a computers GPU you can't trust it.

It looks to me like an "aliasing" problem.  I am suggesting you search ( google, speak to other users using the same workflow you are, etc. ) about " aliasing " problems with your display of rendered pro res 422 files.  If you focus on 'aliasing' issue, instead of calling it half resolution and so on, it probably will address your problem faster because people with that problem will know what you mean.

I posted this earlier and gives a hint what I am referring to.

http://forums.creativecow.net/thread/2/1007725

I am wondering if in the render of the source ( pro res 422 render ) you are losing that color information indicated by the " 2 ".  As you dont experience problem using animation and pro res 444, that is my guess.. that you are losing the color info...hence the problem of aliasing.

What blows my mind though , is that you don't see the aliasing when you go to AE with the same rendered file.  That is just downright weird.

I don't know if you want to actually solve the problem ( find out why this is happening really )... or if you are just fixated on blaming the software for something you want to work differently.  I think solving the problem may involve doing some more steps on your part.  For example, have you taken the rendered file ( or ftp to someone etc ) to another computer like yours... to see if they also see the same thing ?

If they don't see the same thing, if it is OK on their computer, then maybe it's your graphic card or graphic card 'settings' causing the problem.

Have you spoken to anyone at an apple store about this ? They may have heard of this problem from other users... and if you have a store nearby, you can take the rendered file there and see if it looks OK on their computer.

I do wish you luck finding out whats going on, and am personally interested in what you find out ( which is why I keep looking at this thread ). I know lots of people who use pro res and also use it on motion picture 'sets' while shooting... at the DIT station or at video playback, to look at basic playbacks ( usually with some basic color correction etc , like rec709 or whatever )...So what you want to do is actually being done, but I just moved to MN from nyc and dont work in movie biz anymore and dont want to get involved with hooking you up via ftp to some local 600 people.

First step I think is for you to keep an open mind and start dealing with the aliasing issue and try to see if others see the same thing on similar machine as yours.

Or else think of some other way to solve the problem... cause nobody else I know has ever seen this or I would have heard of it I think.

Also, this is a users forum, not adobe technical support... have you called them ?  So please be patient with users here trying to help you, as we are just people who try to help when we can and don't work for adobe.

Thanks and good luck, and please let us know what you find out cause this problem is very weird.

just googled some more...found this , and they are calling it 'pixelated edges'... which would be another word to use in google search for answers...

http://blog.bertonevisuals.com/page/3

excerpt:

Some people are emailing me asking if it is really worthy to shoot with the Alexa and the Codex. My answer is: it depends! Some people might be happy to shoot Apple Pro Res in Rec 709 color space and just edit the clips right away in a non linear editing system. However, if somebody wants to do color correction and subsequent grading, the Arri Raw workflow is strongly recommended. Indeed, is not just a matter of the higher resolution 3K vs HD, but more importantly, it’s the ability to pull perfect keys during DI that otherwise (with the Pro Res) would have pixellated edges. The Arri Raw allows you to change the EI (exposure index) and the T stops that otherwise would give you much less latitude to play with, even if the footage was shot in Pro Res Log C.

OK...off to food shop...good luck