Dunno if I'm making a school boy error with this or not. Not been using Macs that long so go easy on me. cheers. Ive searched the forum but not found a similar post. Ive got a Macbook and a PC set up with a Belkin OmniView Soho serives KVM switch (USB/VGA) running thru a Dell 2005FPW monitor. Now the PC runs fine at 1680 x 1050 (the max res for the DELL) but the mac is not showing the desktop properly. When i use screen mirroring it truncates the image and clips off the top and bottom. Mirroring on running full res 1680 x 1050 (purple areas are wasted space) Mirroring on running full res, this time its centred the image. If i turn mirroring OFF it will show the extended desktop at the correct 1680 x 1050. extended desktop/ Mirroring off The Dell has its own controls that run a Auto Adjust under Image settings, but this does sweet FA. I've defaulted to factory settings on the DELL and still no joy. The mac does recognise the Dell in the display prefs and shows its max res as 1680 x 1050. Any ideas whats going wrong? Just to point out the cables used my the KVM are belkin VGA/USB cables and ive swapped them over to make sure one is not dodgy. Ive ran the Macbook via the KVM switch and as a direct connection to the DELL and it still has the same errors. thanks again.