I have 2 monitors. One rated at 1400 x something and the other rated at 1920x1080. I had been satisfied and happy before mavericks. The 1920 monitor worked great. as soon as i upgraded, i got a huge black bar on the left and a small one on the right and now system preferences dosent recognize the 1920 x 1080 res. I have to alt click it and the same problem arises. What changed in mavericks and how do i fix this?