One thing to consider is people with 1024+ resolutions often have another page or messenger open on a side of the screen, making them shrink the browser window a bit - with an 800 resolution, it would be more compact and there wouldn't be as much squashing of the screen or need for a scroll bar.
Good point. We used to cater for 800x600 viewers but we felt that the number of Users using that display size were not many and / or active enough here to make the difference. Also, we need to accommodate new information and 800x600 was just too confining. Maybe for those who use that size and have panels they can close the panel when on our site? Our minimum now is 1024x768.