Originally Posted by zander
@SysGhost: this is the expected behavior, and the TwinView Xinerama extension data does not imply any specific screen priority/ordering - window managers, etc., shouldn't assume that the first "screen" reported via the extension is the highest priority one on which to place the login screen, etc.; they should really allow users to specify the "screen" priority/ordering. Future NVIDIA UNIX graphics driver releases may allow users to change the order in which specific display devices are reported via the TwinView Xinerama extension as an enhancement, but the current behavior isn't technically a bug.
You are wrong. This isn't a window manager issue, but a driver issue. It determines which monitor in TwinView gets primary output from the X driver, and as of now this cannot be changed whether or not you use Xinerama. It gets more annoying in TwinView Clone with an LCD and TV-Out, where TV-Out is ALWAYS the primary output, and things like Xv and OGL have to be pulled away from it to work halfway right on my own computer monitor!