i have a dell st2410 monitor. and it only shows at 1600x900 resolution while my mbp 15 (2011 i7 2.0) shows at 1680x1050. am i missing something here? i have mirroring off. i bought the monitor knowing that it supports 1920x1080 resolution. im also using the hdmi connector whiile using a belkin mini displayport to hdmi adapter. thanks in advance.