If adjustment is made to the spin button step and page values we see the following bug appear. Though the single stepping works fine, when you click and hold down the mouse button for faster stepping, metacity crashes after a visible refresh of the whole dialog box.
https://bugs.launchpad.net/ubuntu/+source/metacity/+bug/86436 -- Number of workspaces number-field arrow buttons dont work. https://launchpad.net/bugs/83334 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs