As reported in LP: https://bugs.launchpad.net/ubuntu/+source/hal/+bug/212733 by Adrian VELICU the brightness controls for Dell laptops don't work, or do too much.
No ACPI method found
The kernel is 2.6.24-15-generic on Hardy Heron.
The output of lshal -m can be found here:
If you have any questions don't hesitate to ask, but please have a look at the bug and its duplicates first.
1) you can't run the HAL scripts manually, they are supposed to be called by HAL only
2) proc isn't supported by HAL anymore, at least not the interfaces from the generic video module
3) where is the output of lshal? Which desktop environment was used?
4) the two keyevents for brightness are from the kernel. HAL can't do anything here
5) try to unload the video module and use the dcdbas module instead, which allow the whole brightness handling especially for Dell machines.
I'm sorry for the late response. I've been very busy lately and kind of forgot this bug. My excuses.
There are two lshal -m files:
They're both the same. Do you need also the output of 'lshal'? They're using GNOME.
It seems also to happen with Fedora 9.
I'm thinking it could be a duplicate of bug https://bugs.launchpad.net/ubuntu/+source/linux-source-2.6.22/+bug/74284 ,which indeed is solved by blacklisting the video module. But I'm waiting for the replies of the people in the bug report before I mark it as a duplicate.