Views and default values

 Hello.

 I have a problem (one more ;) with views, rules for inserting and default
 values.

 Data Base:

     create table foo (
        cod            serial primary key,
        explication    text,
        silly        bool default 't');

    create view v_foo as
        select * from foo;

    create rule v_foo_ins as on insert to v_foo do instead
        insert into foo values (
            NEW.cod,
            NEW.explication,
            NEW.silly);

 What is my problem with this?... It is easy to make insert in 'foo' with
 default value:

     # insert into foo(explication) values ('Because is in love');

 But, what about 'v_foo'? If I make:

     # insert into v_foo(explication) values ('Because have not slept');

 I don't get default values properly because insert rule is forcing null
 values. In fact, in this example I don't get nothing except an error for
 trying to insert null value in primary key field.

 Is there any way of resolving this problem?. Perhaps NEW might pass a
 'default' value when it doesn't receive any data? have I lost some
 important concept?...

 Thanks.

                                 David