Default values not working

If I add a field to a colum using:
    alter table mytable add column myint int not null default 0;
The default value does not seem to make it into the data dictionary.

This is using Postgres 6.5.

Is there is way to manually poke a default value into the data dictionary?

Bryan White
ArcaMax Inc.
Yorktown VA
www.arcamax.com