So, i tried to compile xcalib this evening, but i failed with an error of an uncompatible version of an fglrx-library. Then i tried dispwin with setting "export ARGYLL_IGNORE_XRANDR1_2=yes" before loading the profile and currently everything seems to be okay now. I didn't really understand, what's different now and why this problem happens at my computer, but if it keeps on working i'll be happy :-) Regards, Sven