PostgreSQL does not have IF(), use CASE instead

I am using postgresql. Admittedly, I'm not certain if this is a subscriptions issue, or a core issue.

If I navigate to my subscription tab (/user/1/subscriptions/node), and click on pages/threads, I get the following:

PDOException: SQLSTATE[42883]: Undefined function: 7 ERROR: function if(boolean, integer, integer) does not exist at character 464 HINT: No function matches the given name and argument types. You might need to add explicit type casts.: SELECT n.nid AS nid, n.uid AS uid, n.title AS title, n.status AS status, n.changed AS changed, s.send_interval AS send_interval, s.author_uid AS author_uid, s.send_comments AS send_comments, s.send_updates AS send_updates, ncs.last_comment_timestamp AS last_comment_timestamp, IF(s.send_comments + s.send_updates = 0, n.created, IF(s.send_comments + s.send_updates = 2, IF(n.changed > ncs.last_comment_timestamp, n.changed, ncs.last_comment_timestamp), IF(s.send_comments = 1, ncs.last_comment_timestamp, n.changed))) AS latest_activity FROM {node} n INNER JOIN {subscriptions} s ON CAST(n.nid AS VARCHAR) = s.value LEFT OUTER JOIN {node_comment_statistics} ncs ON n.nid = ncs.nid WHERE (s.module = :db_condition_placeholder_0) AND (s.field = :db_condition_placeholder_1) AND (s.recipient_uid = :db_condition_placeholder_2) ORDER BY latest_activity desc LIMIT 50 OFFSET 0; Array ( [:db_condition_placeholder_0] => node [:db_condition_placeholder_1] => nid [:db_condition_placeholder_2] => 1 ) in PagerDefault->execute() (line 79 of /mydrupalpath/includes/pager.inc).

I don't believe it is related, but mention it here in case it is helpful. In the d6 version of subscriptions, I could go to "/user/5044/subscriptions/" to view that person's subscriptions. When I try this in d7 (and I have all the relevant permissions set), I get an access denied error.