Function Missing?

Dear Team,

I wrote recently describing a problem backing up my database. I believe
that I have
found the reason why the error is occurring, but i'm unsure how to fix
it. Any help would be
appreciated.

I have the error;
gettable(): relation 'genuser': cannot find function with oid 773217 for
trigger check_user

I think I may have found the answer. I have tried to list the functions
that the database has, using
\df, and the check_foriegn_key function, which I believe is part of the
Postgres database does not appear.
If I delete the trigger which is causing a problem, a new error with
another trigger appears. This trigger also
calls check_foreign_key.

Should this function 'check_foreign_key' appear on the list? Is this the
way to display it?

If it is missing, I would have to reinstall it. Is it possible to
reinstall just specific functions?

and lastly, Am I correct in thinking that functions have oid's as well
as field rows. Or could this error actually
be due to missing some data from a table? (This backup program has
worked before, but has just stopped working!?)

I know I have recently been asking lots of questions, and I do
apologize.

Take Care ~ Keep Smiling,
Luke Tudor.

luke(at)luketudor(dot)com