Fedex Error with phone number?

hi all, i have installed the fedex module 1-3-7.zip ,

i keep getting blank screen once i try to setup the phone number. ( I input a random number for my Fedex account number as i dont have one yet.)

once i key in my number, when i try to checkout, i get a blank screen. if i dont enter my number, i get the message' You forgot to set up your ship-from phone number, this can be set up in Admin -> Modules -> Shipping'

can anyone help me please? thank you.

Are you running 1.3.8a Zen? If so are you sure this mod works with it?
Could you use the FedEx XML module?

im not sure if it works with 1.3.7...from the searches, i got an understnding it will work with some configuration.. anyone can confirm? thank..

and yes, im using 1.3.8a of zencart