Dual-monitors revert to mirror, and shortcuts disappear

I have an Alienware m17x laptop (Dell) running Win 7 Pro 64-bit. I have it set up to output to an external 22" monitor as a two-monitor setup, and the monitors are set to extend the desktop across both monitors.

Occasionally it will suddenly revert to mirroring the desktop on both monitors. After I go in to the setting I change it back to extended desktop, but my wallpaper disappears (desktop is black). Although the taskbar is still there, and works fine.

This also, possibly, has caused desktop shortcuts not to display. I generally don't keep any desktop shortcuts. all the default ones are set not to display, and even my recycle bin is on the taskbar, but if I go to an .exe file in explorer, or even from the start menu, and choose Send > To desktop as shortcut, _no_ shortcut appears on the desktop.

I looked in my actual desktop folder, and all the shortcuts are there, they just won't appear on the desktop!

Any ideas? I know there are problems with Dell computers and Win 7 as far as graphics go, is this just another Dell quirk?