when i boot up games.. l4d2 counterstrike etc i would usually play in 1920 x 1080.. but at the minute it wont let me go past 1600 x 1200 4:3.. or 1600 x 900 in 16:9 widescreen.. the monitor is a native 1080p monitor :s and i have no idea whats going on! any one had this problem ?