some customers are able to checkout without a shipping address + shipping cost - need help

[jasyn]

perhaps someone on the forum knows what is going on. some people who checkout on my oscommerce website are able to complete the checkout process without having a "delivery address" and therefore not getting a shipping cost. is there a exploit or something that i do not know about that allows these people to do this? i'm pretty certain that the address is a necessity, so i don't get how they are getting away with this!

 

i do not believe it deals with paypal wpp as it happens with both paypal express payment and regular paypal direct payment.