75Hz Refresh Rate in XP but not Vista...what???

[dreadman]

Hey everyone.
I have 2 machines hooked up to an AOC 19" LCD via a KVM switch.
On the machine running XP Pro and a Geforce 6200 AGP card, I can achieve the native resolution for the monitor which is 1440x900 @75Hz.
However on the machine running Vista Ultimate and a HD4870 with Catalyst 8.12, if I force the native resolution,
the desktop cuts off about 2-3 inches top to bottom on left side. And checking the monitor info, it states the resolution is something like 1152x900.
Highest refresh rate I can get is 60Hz.
I can't remember noticing this before I just assumed it was running at native.
Is this an issue with Vista? I've read that lower refresh rates can cause eye problems and would like to avoid if possible.
Thanks

 

[GarfieldtheCat]

Lower refresh rates on a CRT can cause problems such as visible flicker, and cause eyestrain.

LCD's are a different tech, and don't have this problem, so they can and should be run at 60hz.

 

[dreadman]

Thanks for the reply.
While that does indeed put my mind at ease somewhat, being the curious person that I am
I'm still wondering why it is not able to achieve native resolution under Vista.