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