warning: pg_query(): Query failed

hi,

i'm setting up a forum that's connected to postgresql 7.4.2 (via
drupal.org framework) and i'm getting some errors. here's the link,
followed by the errors verbatim:
http://128.32.146.140/dmap/?q=forum

warning: pg_query(): Query failed: ERROR: invalid input syntax for type
boolean: "2"
CONTEXT: PL/pgSQL function "if" line 2 at if in
/Library/WebServer/Documents/dmap/includes/database.pgsql.inc on line
104.

user error:
query: SELECT DISTINCT(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 /*! USE INDEX (node_comment_timestamp) */,
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 AND '1' ORDER BY l.last_comment_timestamp DESC LIMIT 1 OFFSET 0
in /Library/WebServer/Documents/dmap/includes/database.pgsql.inc on
line 121.

any ideas?

here's my system:
- drupal v4.5.1
- mac os x server v10.3.5
- postgresql v7.4.2
- php v4.3.6

thanks,
aaron