I have a Macbook 5.1 with Snow Leopard, and a Samsung SyncMaster 2253BW that I use for an external monitor. I connect it to my laptop via a DVI-to-MiniDisplayPort adapter. Whenever I try to set the resolution of the monitor to 1680x1050, its maximum resolution (at least the only one that fills the entire screen), the screen flickers once or twice before claiming there is no source attached.

I've had this issue since the first time I tried to connect the two, however for some reason for a brief period in time the monitor would successfully display at full resolution. All lower resolutions work fine too, it's just at 1680x1050 that the problems occur.

Any ideas as to why this is happening? Thanks.