Looks like your Tcl library and data model are out of synch.
http://cvs.openacs.org/cvs/openacs-4/packages/dotlrn/tcl/navigation-procs.xql?rev=1.1.2.2&view=markup
That shows where the hidden_p attribute was added to that query.
It appears to be part for dotlrn 2.1.3 final.
The portal pages table is created in
http://cvs.openacs.org/cvs/openacs-4/packages/new-portal/sql/postgresql/portal-core-create.sql?rev=1.4.10.1&view=markup
And dotlrn 2.1.3 final version should include that column.
It appears there is no upgrade script from versions prior to the new-portal package that goes with dotlrn prior to 2.1.3.
Something like this
alter table portal_pages add hidden_p char(1);
alter table portal_pages alter hidden_p set default 'f';
update portal_pages set hidden_p='f';
alter table portal_pages alter hidden_p set not null;
alter table portal_pages add constraint portal_pages_hidden_p_ck check (hidden_p in ('t','f'));
