Comment 18 for bug 528094

I have attempted to duplicate your issue on Lucid however the issue did not occur. I may have done something different then you though.

In attempt to recreate the bug but failed I did the following steps.

sudo apt-get install xscreensaver.
sudo apt-get remove gnome-screensaver.
Launched screen-saver preferences. System> Preferences Screen-saver.
Clicked on file Lock screen now.

I have not attempted to let it automatically lock. Is that the issue you are working with? What steps would I do to recreate your issue?

I have also removed the gnome-screen-saver bug report from the log as your issue is with xscreensaver.