The adjustable rear wing problem on Mercedes' 2011 car might not be fully fixed until the Turkish grand prix next month.
Michael Schumacher and Nico Rosberg both had problems with the movement of the moveable flap in Malaysia as they settled in the middle of the grid.
According to Auto Motor und Sport, the problem is arising when the drivers trigger the wing to fold back into the normal position before a corner.
Engineers have designed the wing to return to normal downforce within 50 metres of the pressing of the foot-pedal, but on the W02 this is not always occurring.
"The balance can be disrupted by two to three per cent, which is enough to affect the drivers," admitted team boss Ross Brawn.