Sorry Paolo, but once you have a dead there is nothing you can do..... if it's stuck i.e. shows up either as red, green or blue, then you maybe able to massage it out very lightly with a cloth......
If that doesn't work, then I'm affraid you're stuck with it....... Apple won't consider replacing it until atleast 3 pixels (that's what Apple UK told me) are either dead or stuck.....
I feel your pain though, when I first got my TiBook, I had one stuck pixel, I complained and was told the 3 pixel rule, and then over 3-4 months, my pixels just started blowing..... in the end, I had a cluster of 60+ stuck pixels, so I sent it for repair, and when I received it back, the screen had 2 dead pixels, and another has just stuck.....!!! Grrrrrrr..
I've just changed my desktop image though to hide the problems......!!!
