Samsung Galaxy Ace portable hotspot error

My wife has been using Samsung Galaxy Ace for a year now. But several
months back she always got an error when switch on portable hotspot
feature. Nothing that I did would resolve it. The original firmware
was 2.2.1.

A week ago I updated the firmware to 2.3.5 and the portable hotspot is
working fine now.

I think the problem lies in the old firmware. Nevertheless I can not
justify what went wrong. Still, it is good to have this feature back.

Full Steam Ahead as PLN Targets Geothermal Power

Coal-powered plants account for around 42.2 percent of that capacity, with diesel-fired plants 23.7 percent, gas 22 percent, hydropower plants 6.7 percent and geothermal and other renewable energy at 5.4 percent. -- Excerpt from The Jakarta Globe

I personally think that coal power plants will still play major role in 10 years due to lower capex for development. Challenges to balanced energy mix would be economic scale and ROI. If new technology offers lower development cost then energy mix portion will shift to non-coal based.