PostgreSQL If() function error and INSERT error to "node" table

Enviroment
WinXP
PostgreSQL 8.0.3
Drupal 4.6.(1-3)
Brand new install

I create some Forum container (q=admin/forum/add/container)
and some forum (?q=admin/forum/add/forum)
Then visit this url : ?q=forum
I got many errors

warning: pg_query() [function.pg-query]: Query failed: ERROR:  function if(integer, character varying, character varying) does not exist
HINT:  No function matches the given name and argument types. You may need to add explicit type casts. in c:\...\drupal\includes\database.pgsql.inc on line 45.

user error: 
query: SELECT n.nid, l.last_comment_timestamp, IF(l.last_comment_uid, cu.name, l.last_comment_name) as last_comment_name, l.last_comment_uid FROM node n, node_comment_statistics l, users cu, term_node r WHERE  n.nid = r.nid AND r.tid = 1 AND n.status = 1 AND n.type = 'forum' AND l.last_comment_uid = cu.uid AND n.nid = l.nid ORDER BY l.last_comment_timestamp DESC LIMIT 1 OFFSET 0 in C:\...\drupal\includes\database.pgsql.inc on line 62.

I solved this problem whit this function:

CREATE OR REPLACE FUNCTION "if"(integer, text, text)
RETURNS text AS
'
  SELECT CASE WHEN ($1<>0) THEN $2 ELSE $3 END;
'
LANGUAGE 'sql';

When i make some forum with the first account ((Administrator) users.uid=1)
and logout, and login like a pure user (not anonymus) and post a message to the forum.
error message:

warning: pg_query() [function.pg-query]: Query failed: ERROR:  invalid input syntax for integer: "" in C:\apache2triad\htdocs\drupal\includes\database.pgsql.inc on line 45.

user error: 
query: INSERT INTO node (title, body, format, uid, type, teaser, status, moderate, promote, sticky, comment, created, changed, nid) VALUES('sdafds ', 'dsf saf ', '1', '2', 'forum', 'dsf saf ', '1', '', '1', '', '2', '1124227407', '1124227407', '43') in C:\...\drupal\includes\database.pgsql.inc on line 62.

warning: Cannot modify header information - headers already sent by (output started at C:\...\drupal\includes\common.inc:384) in C:\...\drupal\includes\common.inc on line 192.

IMPORTANT
Have no error If I use the Administrator account, just with the authenticed users.

I think the INSERT statement is not correct.
Tabale declaration:

moderate   int4           not null default 0,
sticky     int4           not null default 0,

but the INSERT sql
moderate=''
sticky=''

I modyfi the node.module file

//Line +-410 in function node_save()
  //I have many INSERT at 1 page request
  static $db_url_array=NULL;
  if($db_url_array==NULL){
    global $db_url;
    $db_url_array = parse_url($db_url);
  }//if

  // Apply filters to some default node fields:
  if (empty($node->nid)) {
    // Insert a new node.

    // Set some required fields:
    if (!$node->created) {
      $node->created = time();

and modify both "Prepare the query:" section (Insert and update)
insert:

    foreach ($node as $key => $value) {
      if (in_array((string) $key, $fields)) {
        if(($url['scheme'] = 'pgsql')
        && ($key == 'moderate' || $key == 'sticky')
        && ($value == '' || $value == NULL)
        ){
          $value=0;
        }
        $k[] = db_escape_string($key);
        $v[] = $value;
        $s[] = "'%s'";
      }
    }

update

    foreach ($node as $key => $value) {
      if (in_array($key, $fields)) {
        if(($url['scheme'] = 'pgsql')
        && ($key == 'moderate' || $key == 'sticky')
        && ($value == '' || $value == NULL)
        ){
          $value=0;
        }
        $q[] = db_escape_string($key) ." = '%s'";
        $v[] = $value;
      }
    }

Now work fine.