Hi
Yes, thats the same thing I experienced. Before 1.03b this sound was not present. XanderF describes the problem very well. It is related to the 2d interfaces. Hit f5 and its gone. It is not a fan sound, but I have no idea why it happens or how a gfx card can squeal at all...

I'm not totally sure if it is the gfx card, my first thought was on the hdd. Power supply? Perhaps, I have to put my ear close again when I'm home from work.
Cheers Porphy