texture readback: I don't understand error messages in max window

Hi all,

I'm giving texture readback and shared contexts another try. It seems things have improved, but here is something I don't understand.

In the following patch I render twice on one render context, both times with a different shader. When I enable the metro I first see a stream of error messages. But once I assign the captured texture to an object, the errors disappear.

Steps to reproduce are inside the patch. It would be great if someone could explain me whether I do something wrong or this is a bug in jitter.

Thanks,
Mattijs

(note, please save and open before use)