Please describe the problem:
I am using an NVidia card with TwinView across two monitors that are not the same size. Compiz correctly recognizes borders, and blacks out the excess virtual space, but Nautilus allows icons to appear in it.

One monitor is 1440x900 (laptop screen, default, bottom-left), and the other is 2560x1600 (large monitor, right). The orientation of the two creates a 1440x700 "pocket" above the laptop screen of virtual screen space.

Since it is at the top left, when programs dump a file in $HOME/Desktop, the file icon appears in this "pocket" that is not visible on the screen.

Currently the only way to bring the lost icons back to visible space is to open a separate nautilus folder window to $HOME/Desktop, find any icons that are missing, and drag them onto the desktop in a visible area.

Steps to reproduce:
1. Set up a dual-head system wherein the two monitors are not the same size, e.g. a laptop screen left-of a larger, normal screen. Move the smaller screen to the bottom of the virtual desktop space.
2. Open a terminal to $Home/Desktop
3. type "touch myfile".

Actual results:
It does not appear on screen since it has been placed in the excess virtual area above the left viewport.

Expected results:
the icon should appear in the top left *of the primary viewport*, and never in virtual area.

Does this happen every time?
Yes

Other information:
I'm moving this upstream from here: https://bugs.launchpad.net/bugs/360970

Since I am using TwinView/NVidia, I'm uncertain if this effects me because of the proprietary driver. However, since all window snapping and spawning rules seem to be applied properly, it seems that this is not an issue with those.

The mouse is not barred from entering the "pocket" either, however this part is most likely not a bug with nautilus, and instead with Compiz/Metacity/X11.