While doing my animation tests with Sintel, I noticed an annoying problem where the animated playblasts would not show the most of the textures, and yet the still OpenGL renders would.
Over the past few evenings, I've been chasing this bug quite fruitlessly, placing debug prints all over hoping that it was just some missing/different statements in the drawing code but to no avail. Finally, I suddenly had a moment of inspiration, and decided to check the file to see what differences could be found between the objects that worked and those that didn't were...
It turned out to be the Mask Modifier! *shuffle* *shuffle*
Obviously there must be something that I've forgotten to do there, which is making this fail. But what that is will have to wait till tomorrow. Unless someone reads this and decides to pick up the debugging from here :)