Re: TwinView support for 5120x1600
Hmmm...it says in the notes for 8756 release highlights that they "Added ability for OpenGL applications to span greater than 4096 pixels when in Xinerama." However, that says nothing of the ability to *display* resolutions greater than that (furthermore, does that TwinView setup use Xinerama? Been a while since I've used multiple displays).
Obviously, make sure you using the latest drivers...good luck.