Christopher, do you mean BIOS version 2.53? That's the newest I could find. Anyway, by updating to 2.53 (from 2.52) and removing the 'GRUB_CMDLINE_LINUX="acpi_backlight=vendor"' line from /etc/default/grub, it now works as expected.
Thanks for the suggestion! Just for reference: eeroz@eeroz-ThinkPad-W530:~$ sudo dmidecode -s bios-version && sudo dmidecode -s bios-release-date Swipe your right index finger across the fingerprint reader G5ET93WW (2.53 ) 05/24/2013 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1173352 Title: [ThinkPad W530 2447] Brightness keys don't work as expected on To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1173352/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs