According to todays Wall Street Journal, there is a safety problem with the in seat power ports on certain aircraft. UA is (temporarily) turning of their in seat power ports on 777's (the rest of their fleet is not affected). UA says they will rewire 24 777's plus wire all 767's and most 747's by 2001. (it currently has 104 planeswer ports). A maintenance check at UA apparently showed that the wiring for the in-seat power was too close to other wires that supply backup power to various parts of the aircraft.
Also, due to concerns with electrical malfunctions, UA is prohibiting laptop recharging on its 777's. UA says they won't reconnect the units until wiring fixes are complete (around the end of the year).
There was problem with a power port on an international AA flight (sparking from an outlet)that resulted in a diversion to Shannon. AA is also rewiring its entire fleet.
The article is on page A3 of todays Wall Street Journal.