have you checked that your plane you create has the same proportions as the blueprint? eg. if your blueprint has properties 1600 x 1200 pixals then create a generic plane size of 1600 x 1200.
failing that... there are heaps of tutorials on the net for setting up blueprints. google them and you'll be set.
you should use imageshack or something like that to upload your image so we can see a screenshot of your problem.