Forms printing via Crystal9

Our company prints multipart forms such as installment contracts. These forms are longer than 11". I have 2 machines giving different results. Both cpu's are XP Pro, both use Generic 9 Pin printer driver set to use custom long paper size, both using same software and same forms. One cpu will print the entire 8.5 x 21" form; the other will only print 8.5 x 11". Any ideas?

Thank you