I am by no means an expert, but I have taken a look at your .css file. Your page structure is very similar to mine. One glaring thing I see is that your wide and narrow columns width is greater than your header image area. That is one reason that your right column isn’t floating right next to your left column. It looks like the total width of your page is 760n pixels, but your narrow column and wide column add up to be 450+550 pixels= 1000 pixels. That could be a reason why it isn’t displaying properly. Again, I am NOT an expert, but I can see that one error. Be sure to backup your file as it is now BEFORE messing with anything, so you don’t lose your data. Good luck!
Checking the validator shows a number of issues.
