Sometime last year around September time I started having problems downloading content from the Xbox website. Whenever I downloaded something via the website the console would say that it was assigned to another console and not download it. Like most people, I have had several Xbox consoles so I just thought this was a DRM issue and the website was confused by my previous consoles. Several calls to Xbox support never got the problem fixed and it was forgotten about. When I got my new slim console last week I was still having problems transferring new content so back onto support who have called me today to say they have transferred all of my content to new console. However, it has not worked. I purchased Beyond Good and Evil on the previous console and when I go to downloads on the xbox after setting download via the xbox.com website it gives an error “Assigned to other console” and it doesn’t download. If I press A and try and continue it will let me continue but it will not download until I intervene. 
Now the second screenshot will make you want to pull your hair out. I just tried downloading the Saw 2 demo which I have NEVER downloaded on any console ever so its not assigned to any previous console or anything like that – gives the same error via the website – assigned to other console and download is stopped. Again If I tap through I can download it. 
So as you can see, this is a very strange problem. I have never downloaded saw 2 demo. Just to double check, I tried the PES 2011 demo and the same error. I can understand if its confusing content I previously purchased, but here is evidence that brand new content I have never downloaded before thinks I am on another console. How weird is that? So since September I have not been able to download anything from the website at all without it being interrupted by this error. If I download via the console, its not a problem and I don’t get the error. Now it is no major issue as I can download via console, but sometimes I do want to get stuff via the website but it does not like me. Has anyone got any ideas please on what the heck is going on?
UPDATE: Always ask twitter if you have problems and not Xbox support.
Issue fixed by this step from @jochta http://j.mp/lDr5Xn
You pay I Keep says:
It’s a paranoid DLC DRM problem, It will always occur and xboxlive
knows about it; they will not fix it for you.
The problem is that the DLC content you have paid for doesn’t actually
belong to you & it cannot be moved from one console to another without
Jumping through MS hoops. Even when you do successfully transfer content
will still find some games won’t work and the games that do work will only work
when connected to Xlive. The only way to get them to stop with
the DRM is to stop buying the DLC until they free it up; I suggest you give up
for now & only buy your games & expansions on retail discs.
This way will insure you the freedom of true ownership.
Good luck.