Gnome missing on second display in dual card setup

[MR ZenWiz]

On Fri, Jan 7, 2011 at 11:46 AM, Fredrik Jonson <fredrik at jonson.org> wrote:
>
> Seems like gnome somehow is aware of the left screen after all, just
> unable to start a session on it or something.
>
I think you have to use a smarter screen manager, maybe xinerama.

I have two monitors on the same graphics card and I get screwy results
with it, but both screens work.

I'm using the native nvidia driver (which won't help for your ATI
cards) and that forces me to use xinerama if I want both displays to
work.  The strange part is that I have the "top" panel on the right
side, but it is on the right side of the left panel (and it anchors
there), but windows can go behind it onto the right panel and fill
that up without any trouble.  It seems to treat them as two separate
screens on the same desktop.

I have tried using them as a single continuous desktop, which is the
only way they work without xinerama, but that has other difficulties
(like things showing up in the center of the virtual screen, thus
being split onto both panels making them hard to read, and having a
too-wide expanse for vertical panels to work well).

What combinations of monitor setup have you tried using the
System->Preferences->Monitors and System->Administration->Display
settings?  (On mine, the Monitors doesn't work because xinerama
clobbers RANDR, and the NVidia X Server Settings show up in both
preferences and administration....)