Microfish

Hello, I have a xj700T mag monitor, an STB Velocity 4400 videocard, and a be6-II motherboard.
I cannot get the display on my monitor to reach the max 17 inch crosswidth. Its vertical hieght is fine. But the horizontal is abour 2.5" too small.
I've spun the monitor resize dial, but it have already reached maximum horizontal width. I loaded drivers from the STB web site, and have tried the ones that came with the video card. What should I do.
I'm not sure if its a hardware or a software prob, because when I was installing windows, it worked fine (initially). But after I finish setting up the drivers and removing any conflicts, it starts to do the small size thing again. Upon startup it still works fine. Its when it reaches the desktop, it resizes, as usual, but to a smallar width. Anyone have any suggestions as to how I can figure out what the problem is? (I've tried changing the colors and screen area...now at 16 bit high and 1024 x 678 pixels)