After 1,5 years of total happiness with my MAC, I am kind of pissed now. Seems as if something is wrong with the graphic card. I don't have f*cking glue what is going on and I hope, it doesn't get worse, as I still can use it more or less "properly". Being located in Spain and just coming home for the christmas days, there is no chance for me to get it repaired or something, as it is totally neccessary for me to have my Macbook with me here in Spain.
So please cross your fingers, that it keeps running at least in this status as it works right now and won't get worse. :-/