I have a 30" monitor (3007WFP) and a Dell D630. The stock (on board) video chipset does not run th monitor at 2560x1600. It's max resolution is 1920x1200. Onboard Chipset: Intel 956 Express Chip Family.
I acquired a D/Dock port replicator that has a PCI slot in it. I went to Best Buy and bought a $99 BFG - GeForce 8400GS PCI card.
After installing the PCI card in the D/Dock (with the laptop off) I powered it up docked to the PD01X D/Dock. The Dell BIOS splash screen displays and the progress bar slowly goes completes. But onces the progress bar is complete, the screen flickers then nothing. The screen doesn't change at all. Just the progress bar (full) on the Dell BIOS screen.
I have two monitors connected to the GeForce 8400GS. A Vizio 26" (connected via VGA), and the Dell 30" connected via Dual DVI.
When the laptop (D630) is docked in the D/Dock (PD01X) the internal display does not come on at all. The Vizio does come up and that's who's displaying the Dell BIOS screen. This tells me that the Laptop is seeing the GeForce card and it's working. But like I said it hangs up after the progress bar completes.
If I wait about 2 minutes the laptop shuts off by itself (while on the Dell BIOS screen). When I remove the laptop from the docking station and book using just a port replicator everything is fine (except the 30" runs at 1280x800 _gleck!_).
I've updated the D630's BIOS to version A15 (from A12).