Regarding my last comment[0], i would like to let you know that:
I recently upgraded my ubuntu installation ( 8.04 ) to 8.10 and the bug has gone, i.e. gnome-screensaver works OK even when compiz/gldesktop is enabled.
[0] https://bugs.launchpad.net/ubuntu/+source/compiz/+bug/122084/comments/12
Regarding my last comment[0], i would like to let you know that:
I recently upgraded my ubuntu installation ( 8.04 ) to 8.10 and the bug has gone, i.e. gnome-screensaver works OK even when compiz/gldesktop is enabled.
[0] https:/ /bugs.launchpad .net/ubuntu/ +source/ compiz/ +bug/122084/ comments/ 12