PostgreSQL 8.4 ILIKE does not support bytea column

On upgrading from Drupal 6.22 I got the following error

Update #7011
Failed: PDOException: SQLSTATE[42883]: Undefined function: 7 ERROR: operator does not exist: bytea ~~* text LINE 4: WHERE (value ILIKE 'user\\_mail\\_%' ESCAPE '\\') ^ HINT: No operator matches the given name and argument type(s). You might need to add explicit type casts.: SELECT v.name AS name, v.value AS value FROM {variable} v WHERE (value ILIKE :db_condition_placeholder_0 ESCAPE '\\') ; Array ( [:db_condition_placeholder_0] => user\_mail\_% ) in user_update_7011() (line 715 of /home/rsantos/workspace/staticweb/drupal/modules/user/user.install).

My quick fix was to add the "convert_from" function but I'm sure someone will come up with a better solution.
SELECT v.name AS name, v.value AS value FROM variable v WHERE (convert_from("value", 'UTF8') ILIKE 'user_mail_%' ESCAPE '\\')

Tks