'Ice in fuel' caused BA jet crash

[sharkbit]

Also in one of the first BBC reports to come out after the crash, it stated that the planes captain said that all the aircrafts electronics had failed. Would ice cause this?

No.

Even if the engines quit, causing the electrical generators on the engines to stop producing power, the aircraft is equipped with batteries which can power all of the essential electrical equipment for a fair amount of time-enough to get the aircraft to an airport and land it.
Aircraft are certified with that eventuality covered. Even if the airplane went totally "black"-no electrical power what so ever-the airplane's control systems should still be able to function and the aircraft should still be able to fly. Difficult-yes.(I wouldn't want to be in that situation!)

If ice were the cause and at the high altitudes that jet planes fly, you would have thought there would have been more instances of this type of problem occurring in the past in other aircraft.

Engines are equipped with fuel heaters that warm the fuel prior to it getting to the fuel control unit on the engine. The fuel is heated by the hot oil from the engine. They don't mix-oil and fuel lines pass close together in a oil-fuel heat exchanger, usually mounted somewhere on the engine.

...been as much as five litres within this aircraft's fuel load.

5 litres isn't much. I don't know how many thousands of gallons(Sorry, I'm an American ) of jet fuel a 777 carries, but 5 litres is a pretty small amount and spread out on both sides, it does seem likely that frozen fuel can cause it.

But, stranger things have happened and different factors may have linked to cause the problem.