No double buffering on second screen?
What is the technical reason there is no double-buffering on the second screen on a single-card, dual-head setup? I run my X server with two separate screens (i.e., not twinview and not xinerama), and I get very noticeable tearing artifacts when watching DVD's on the second screen, which I assume is due to it not double-buffering.
Perhaps there's a way to fix this, especially since the nvidia proprietary driver keeps me from using a second (PCI) video card to do 2-D tasks at any reasonable speed. Any clues?