I have a Samsung SyncMaster monitor, which does not show the login screen until after 5 minutes . The computer has no problems. When the display appears there is the password screen, which means that the computer works fine.
This problem occurs sometimes and especially when the computer has not been on for a few hours.
Also, the resolution of the screen gets reduced to 1024x768 (correct resolution is 1440x900). I can't find the right resolution in the screen resolution menu. The monitor is also detected as a Generic non-PnP monitor, instead of Samsung NWZ.
I have reinstalled the graphics driver and also the monitor driver, but the problem isn't solved.