I just bought a new desktop, running on Ubuntu 12.04. There are one DVI port and one VGA port. When I plug in two monitors, the one on DVI does not respond while the one on VGA shows the following:

Attention: Unsupported Video Configuration Detected ACTION is Required
This COMPUTER has an add-in graphics card, but the monitor cable is plugged into the integrated video connector
....

With one monitor plugged in, it is working perfectly. How can I resolve this? Help!Are the two ports right next to each other, or is one vertical and one horizontal?  If the LATTER, the error message is correct - you have one monitor plugged into the graphics card, which is correct, and the other plugged into the onboard graphics, which won't work as they're disabled when a graphics card is installed.  To use two monitors you would need to plug them both into the graphics card (horizontal outputs) if it has two ports.They are vertical. Both of my graphics card and onboard graphics card have one port only.
Is getting a new graphics card with two ports the only solution?
THANKS!