Regression: unity-6.0.X is causing a fine line under the panel & launcher when nautilus is handling the Desktop

Won't be noticed with the default config.

To see, several ways:
Make the unity panel transparent, there will be a file dark line that shouldn't be there. Now disable nautilus handling the Desktop, the line disappears

Enable cube & rotate, switch Desktops with keyboard bindings. The line will show white as the Desktop is rotated both under the pane;l & next to right edge of launcher (launcher at default setting of 'never hide'
Same as above - disable nautilus handling the Desktop & these lines disappear

More obviously is if you rotate the cube 'graphically' as shown in screenshot. The panel , (set to transparent) & launcher area are 'highlighted
Again disabling nautilus handling the Desktop & these lines disappear - 2nd attached screen

ProblemType: Bug
DistroRelease: Ubuntu 12.10
Package: unity 6.0.0-0ubuntu2
ProcVersionSignature: Ubuntu 3.5.0-4.4-generic 3.5.0-rc6
Uname: Linux 3.5.0-4-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 2.3-0ubuntu4
Architecture: amd64
CompizPlugins: [core,composite,opengl,decor,move,imgpng,dbus,text,fade,regex,mousepoll,gnomecompat,place,workarounds,compiztoolbox,vpswitch,snap,cube,session,resize,commands,rotate,expo,ezoom,scale,unityshell]
Date: Mon Jul 16 22:49:32 2012
InstallationMedia: Ubuntu 12.10 "Quantal Quetzal" - Alpha amd64 (20120707)
ProcEnviron:
 TERM=xterm
 PATH=(custom, user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: unity
UpgradeStatus: No upgrade log present (probably fresh install)