I have a PostgreSQL db with the table 'news_article', which has its primary index a serial column named 'art_id'. This table has a row whose art_id is set to zero. Now I'll do the following:

1. Make a persistent connection.
2. Make query of the form: 
     SELECT * FROM news_article WHERE art_id = 0

Most of the time this query will work fine, but if I refresh the PHP script multiple times, I'll eventually get an error with the following error messages.

-------------------
PHP error message:
-------------------
Warning: pg_query() [function.pg-query]: Query failed: server closed the connection unexpectedly This probably means the server terminated abnormally before or while processing the request. .in [filename.php] on line 21

--------------------------
PostgreSQL error message:
--------------------------
pq_recvbuf: recv() failed: Undefined error: 0


Some things I've noticed:

* This problem does not seem to appear when
  connecting with non-persistent connections.

* Although the PHP error message suggests the
  connection was closed prematurely, you can
  still issue successful queries using the same
  connection resource later on in the PHP page,
  so it appears that the connection is still
  open.