Printing wrong size

[nuclearfishin]

Hello, I'm having difficulty printing an image to the correct size. I'm resizing a larger image and making it smaller. The ruler on the screen shows the image as the correct size, but when I go to print it doesn't print the size I'm seeing on the screen. I'm printing an image that is 17" wide using the poster option and printing it on four 8.5x11 sheets. If I open the resized image in microsoft paint, it prints correctly at the new resized image. If I print within Paint Shop Pro, it continues to print at the 19" image size, not he 17" size. I know I must be missing an easy setting but for the life of me I can't find it. Any help appreciated!