Why is photoshop printing small black dots on paper when I make a white background?

I made a picture with Adobe Photoshop cs2, and when I print it out on paper, the white background has some little tiny black dots where it is supposed to be pure white. The background is clean and white on photoshop, so why is it printing like this with black dots? I am printing it from photoshop as a .psd , but I don't think thats the reason. Do I have to save it first as a high quality jpg or something to get rid of the dots that are being printed? The dots themselves do not stand out too much, however, when you look closely you can see them, and if you compare it to a pure white sheet of paper you can see the difference.