probably because of your program reading the dpi wrong. it should print ~7" x 3.5".
set the width to 7" and print super low quality to see it will work, then print high (altho the one you have is proabably low res, based on your program thinking it is 2.5")
set the width to 7" and print super low quality to see it will work, then print high (altho the one you have is proabably low res, based on your program thinking it is 2.5")