Problem
My screen lock preferences contain the following screensaver displays that can conflict with some frame buffer drivers:
Insecure screen distortion screensaver displays
Screensaver displays such as julia and penrose
These screensaver displays occasionally run when I select random screensaver.
Solution
You have an old ~/.xscreensaver file. Perform the following steps:
Remove the ~/.xscreensaver file.
Log out, then log in.
You can deselect screensaver displays that you do not need in the Display Modes tab of the screensaver properties dialog.