I recommend removing the curtain driver from the system settings. That should allow the device settings to be configured again for your 4 monitor display.
Then consider reinstalling Live Mesh, but my gut tells me that you'll encounter the same issue again if the curtain driver is interfering with the proper functioning of you display driver.
-steve
~ Microsoft MVP Windows Live ~ Windows Live OneCare| Live Mesh|MS Security Essentials Forums Moderator ~
Steve is correct there. There are some open issues around the 4+ monitor Remote Desktop and some display drivers not working well with the Mesh remote driver. We've been working to correct this in the next major release.