I Saw This Happening At Fry's Because They Were Using A Single-Link DVI-D Cable. Just To Make Sure, Your Cable Looks Like The One In The Picture Below Right?
Keep In Mind That There Are Two Types Of Mainstream DVI-D Digital Connections: Single Link And Dual Link. For A Single-Link DVI-D Connection, The Maximum Resolution That Can Be Displayed Is 1920 × 1200 Pixels (WUXGA). Higher Resolutions (Such As 2560 × 1600 Pixels) Require A Dual-Link DVI-D Connection Providing Double The Bandwidth Of A Single-Link DVI-D (7.4 Gb/second Or Higher). To Use A Dual-Link DVI-D Connection, The DVI-D Input On The LCD Monitor Side, The DVI-D Output On The Pc Side, And The DVI-D Cable Must All Be Compatible With The Dual-Link DVI-D Standard. Cable Length: 20m