Colorsyncers, I'm not sure of this is outside the domain of this forum but it seems to have the highest proportion of 'experts' so I will try my luck anyway. I've been using an EIZO CG241W for several years without a problem. Lately, it has been scaring me by going into a 'posterised' mode where all the colours look like I'm in 2 bit mode! I thought the video card/processor in the display had given up the ghost however, the effect was/is disabled immediately as soon as I quit Color Navigator. This only seems to have started since I upgraded to Mavericks. I am also getting an occasional message from Color Navigator saying it has reset the gamma. Has anybody else experienced this? Is my monitor telling me something or is it a conflict with the OS? Thanks. Mark