This appears to only effect thinkpads using the Intel x3100 graphics.
I have a Thinkpad 61p with Nvidia Quadro and the brightness control works (updating today's packages), using the proprietary nvidia driver. But when I try my other Thinkpad T61 with Intel x3100 it does not work.
Also using thinkpad acpi option is a bad work around for the real issue. This worked and then broke with an ubuntu kernel update (see my other comments).
This appears to only effect thinkpads using the Intel x3100 graphics.
I have a Thinkpad 61p with Nvidia Quadro and the brightness control works (updating today's packages), using the proprietary nvidia driver. But when I try my other Thinkpad T61 with Intel x3100 it does not work.
Also using thinkpad acpi option is a bad work around for the real issue. This worked and then broke with an ubuntu kernel update (see my other comments).