I'm assuming you did something like this:
Code:
#rightcol
{
left: 800px;
}
Well without looking at your code, this might be an IE bug...did you try looking at it in firefox?
If you keep getting the same error, the best advice is to start with the css/html layout from the book (make sure it's perfect) then slowly change/test/change/test from that point. You'll then figure out exactly what's wrong.