OK I tried an earlier version of the nvidia drivers - 304.123. p roblem remains.
I have tried removing the graphics card and reverting to the on board chip. Problem remains. On borad chip is: 00:02.0 VGA compatible controller [0300]: Intel Corporation 82G33/G31 Express Integrated Graphics Controller [8086:29c2] (rev 10) (prog-if 00 [VGA controller]) Subsystem: Foxconn International, Inc. Device [105b:0df7] Flags: bus master, fast devsel, latency 0, IRQ 44 Memory at fdf00000 (32-bit, non-prefetchable) [size=512K] I/O ports at ff00 [size=8] Memory at d0000000 (32-bit, prefetchable) [size=256M] Memory at fda00000 (32-bit, non-prefetchable) [size=1M] Expansion ROM at <unassigned> [disabled] Capabilities: <access denied> Kernel driver in use: i915 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1385457 Title: "Show desktop" shows remains of previous windows not wallpaper To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/1385457/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs