Give this a try... download Acrobat Reader and the Gigabyte PDF manual from the link above, if you dont already have it, or get out the manual that comes with the board.
If you scroll to Page 15 of the PDF manual, ( Page 8 in the book ) that shows how to set the Dip Switch CLK_SW to Auto FSB or 133 FSB.
If you scroll to page 79 of the PDF manual ( Page 72 in the book ) you will find your FSB and voltage settings. Leave the CPU voltage at default untill you get the FSB settings correct.
Set the DIP Switch to Auto first. Then, go into BIOS and set the CPU to 133 FSB. This would be the best setting. Then you should be able to use higher FSB settings.
Second Option : If Auto did not work, try the 133 FSB setting.
Hopefully this will correct the issue with the CPU not able to run 133 MHz FSB.
Also set your RAM Speed to the correct spec. If you have 100 Mhz SDRAM set to 100
Your video card should work fine with this board.