Just bought LG 22" monitor with native 1920x1080 resolution. Hooked it to my new 21 " imac via the "mini display port-to-VGA adapter." The new monitor itself pops up a window saying "switch resolution to 1080 x 1920 for best performance" but on the apple VGA display window, the list of available resolutions tops out at 1600 x 1200, and even if i try this one it says "D-Sub out of range" I do have it set at 60 Hz. is this a VGA limitation? bottom line: can I get this monitor to work ?