Hibernate version:2.0.3

Hi.
It might seem stupid, but I'm having problems on a one-to-one birectional relationship.
I got table ADDRESS (pk is ADDRESS_ID) and table COMPANY (pk is COMPANY_ID and fk is FK_ADDRESS_ID).
When I try to save a Company object, the information related to the Address object is not being saved (and Company object contains a Address object naturally).
Could anyone post a example of a bidirectional one-to-one relationship for hibernate 2.0.3?
Thanks.