Lost plpgsql function

After copied pg database from one PC to another

    -I could not find plpgsql function(s) in the copied database.
    -had to instal plpgsql language handler again

    -whilst tables and data moved fine

The copy included all under /cygwin/usr/local/pgsql/data and database was
down while making a copy.


What could I forget to copy  as far plpgsql is concerned ?
Are pgsql stored objects stored in the database itself (a table pg_proc,
column prosrc)?
Catalog tables like pg_proc are just a part of database cluster data files,
aren't they?

Thank you in advance, Laimis