We go early Feb for the last two years and early march as well. March was actually colder than Feb for us on those years, so go figure. We had great weather in Feb. Crowds were pretty low EXCEPT the weekend of the superbowl last year that was in Jacksonville. Don't want to put a damper on your trip plans but that is Superbowl 2007 weekend and its in MIAMI. Lots of Dads go two 1/2 hours south for the game and all the moms and kids go to Disney. Just something to think about. We always seem to go on Superbowl weekend and I am glad that there won't be a Superbowl within 3 hours from Disney this year!
Just a thought. If you are able to change your dates I would pick the next weekend. If not, don't worry about it. It still won't be as crowded as say spring break.