9″ mono on 915 chipset?

i find some strange thing about this intel motherboard 915chipset, when we use our 9″ mono (for POS) in a built-in vga 915chipset, it’s over range, but when i connect to other vga card like ati or gforce video card, it’s not having over range problem, all same resolution at 800×600@60hz.
do anyone knows whats in this 915 chipset?
the 9″ monitor has a specs of freq at 31.5-35.5khz (non-interlaces)

btw, i only have 50techpoints available so im giving this questions for 50points but how can i increase this?