Yahoo and Storm

I bought my husband a storm for his birthday on Christmas Eve and he tried to immediately set up his existing yahoo account on the Storm...we he has tried for several days with no luck...when he enters in the address and password through the email wizard thing, it says they do not exist, but when he goes on the computer and types the exact same thing it logs in just fine...when you go to the blackberry website to create a new account, it says to contact the service provider...he did that and they did not help at all...does anyone know anything about this??
Thank you very much in advance for any help!!!