Removed the duplicate status, sorry. I thought they were essentially the same problem. In fact I just tried the solution with an Acer Laptop suffering from the same symptoms and met the same results.
** This bug is no longer a duplicate of bug 68617 bashism in hal-system-lcd-get-brightness-linux -- Brightness control via ACPI in HP notebooks https://launchpad.net/bugs/82188 -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs