Dontcha just hate it when no one replies - and all these coders hangin' out around here too. Sorry, I'm a bit off tonight and will be spending another Tuesday at the VA clinic attached to a machine. I'll try to help with this after I get home.
One quick thought though: think about making a fixed width at 960px - fills a screen nicely for those using a 1024x768 screen resolution and still doesn't look bad at larger. You leave out those still stuck in the 800x600 world though. I don't design for that segment and haven't had anyone complain, but that's not to say no one uses that old setting anymore. Up to you. I just think the great majority use larger resolutions and smaller fixed width designs look lost in a sea of empty pixels. I did opt to circumvent that emptiness by giving wider screens some graphical content to look at on this site:
http://www.linomaster.com/ It looks centered in a 1024x768 screen, but it's actually left aligned. You can see the hidden design appear in wider resolutions.
Later,
Jim