I got a Mac Mini (Late 2009) and a Samsung SyncMaster P2470LHD and this seem to happen every time it’s left off for some time. On the first boot the screen resolution is always wrong: the Dock will be cropped a bit and fonts look fuzzy. Oddly, also the wallpaper changed in the beginning. After I deleted the preferences file for the display and wallpaper settings the wallpaper stays the same.
(What it looks like)
It’s not possible to change the settings to the correct resolution before rebooting. Any settings will look bad on the screen. And, interestingly, the display settings change after the reboot.
I experience this problem since I updated to OSX Mountain Lion and I already deleted the PRAM. I also tried to delete the files in
System/Library/Display/Overrides as I read in a solution to a similar problem but it didn’t help either.
I wonder why this only occurs after the Mac Mini has been turned off for some time.