DeepSave() Issue

When I deep load a UserRole entity then do a bunch of processing setting various properties including changing the UserID (which is a foreign key reference to my User entity) then deep save my UserRole, the UserID reverts to the UserIDSource value for UserID instead of what I've set it too.

 Example

UserRoleService userRoleService = new UserRoleService() ;

UserRole userRole = service.GetByUserID(userID);

service.DeepLoad(userRole );

// at this point UserIDSource.UserID = 1

// do some stuff

userRole.UserID = newUserID;  // eg #2

// do some other stuff 

service.DeepSave(userRole);

 // at this point userRole.UserID = 1 again :(