I had the same problem with an Amilo M6450 and Vista.
Fan always on medium or high RPMs without any load, making the notebook unbearably noisy. Also the battery life was down from almost 2 hours to barely 30 minutes even in power saver power plan.
FSC support were no use: "Vista not supported for this model" - nice!
This is how I solved my problem:
Installed
RightMark CPU Clock Utility (RMClock)
Chose the Power on Demand option, set it to your max friquency, but enable throttling, also enable PSTate transitions in the power plan.
Enable max frequency for the AC Power and all frequencies for Battery Power.
Decreased the voltage of the processor to 0.94 volts at your max frequency in the Profiles tab.
You now have your old super silent notebook, the way it used to be in XP.
My fan only turns on when I put a load on the CPU, works for a while and then completely stops. There is no notable decrease in performance.
If you have another processor (mine is a 1.7 MHz Centrino), you might want to try different frequency/voltage combinations that will work for you.
Allow 2-5 minutes after each combination change for the CPU to cool or heat up.
My battery life in the Power on Demand profile is now 2 hours.
Big thanks to the guys at Right Mark and I hope my experience works for you too.
N