"Apple are very aware of this problem.
It is ocurring to people who have max amounts of RAM in their machines and apparently it makes little difference if it is Apple RAM or 3rd party - it is the quantity that matters.
They are about to release a software update to address it. He said that officially it might take up to a week or two for this to come out but unofficially we could expect it within a matter of days.
In the meantime he said that a solution could be found by removing one of the 2GB sticks and replacing it with the original 1GB - I asked if it was a problem running unequal banks and he said no, only on the MacBooks as they share the RAM with the GPU which these MacBook Pros do not."