Comment 71 for bug 719620

Can you test now removing the toshiba_acpi module instead? It's a shot in the dark and I doubt it may change anything, but as it registers a backlight device too, worth a quick check it there isn't any conflict (anyway it shouldn't cause problems from what I saw).

Also with toshiba_acpi loaded, I think you have two backlight devices inside /sys/class/backlight/, one acpi_video0 and another toshiba. As another test when the system resume from first suspend, try writing brightness value inside /sys/class/backlight/toshiba and see if it changes anything.