Sorry, the way I phrased c) makes it very hard to understand. Here's another attempt:
c) after going into KPowerSave settings and selecting a power scheme on the first tab
"display
brightness" and "CPU speed" are greyed out and marked as "not
supported"
To make things even more mysterious HAL is marked as "enabled". I also looked
at /etc/dbus-1/system.d/hal.conf and I don't see anything suspicious there (though
I'm not an
expert on DBus and HAL).
I also found a thread from 2012 where someone reported identical problem:
http://trinity-users.pearsoncomputing.net/?0::2964 That problem was not solved back then.
Perhaps
today someone can offer a solution.
Janek