StoutFiles - 12:55 pm on Nov 11, 2009 (gmt 0)

I still say you should design in both Firefox AND IE simultaneously. How will you know exactly what in the CSS isn't working properly? Make a change then check them both.

In a scientific test you only want to introduce one variable to the equation to see the effects on the system. Adding more than one and you'll have no idea which variable did what. That holds true with website design as well.