BUG #8295: crypt() function fails randomly

The following bug has been logged on the website:

Bug reference: 8295
Logged by: Dek
Email address: dek(dot)mauleon(at)gmail(dot)com
PostgreSQL version: 9.2.4
Operating system: windows server 2008 R2 standard SP1 64 bit
Description:

crypt function fails with does not exist. This happens randomly and trying
the same command again works.

Verbose Error log:

2013-07-11 12:33:42 CDT LOCATION: pq_recvbuf,
src\backend\libpq\pqcomm.c:839
2013-07-11 12:35:14 CDT ERROR: 42888: function crypt(character varying,
character varying) does not exist at character 80
2013-07-11 12:35:14 CDT HINT: No function matches the given name and
argument types. You might need to add explicit type casts.
2013-07-11 12:35:14 CDT LOCATION: ParseFuncOrColumn,
src\backend\parser\parse_func.c:304
2013-07-11 12:35:14 CDT STATEMENT: select count(*) ct from root.sysuser
where user_id = 115 and (user_login_pwd = crypt('testpass'::character
varying, user_login_pwd)) = true

Running the same command again works:

brazil=# select count(*) ct from root.sysuser where user_id = 115 and
(user_login_pwd = crypt('testpass'::character varying, user_login_pwd)) =
true;
ct
----
0
(1 row)

extension pgcrypto is installed via create extension pgcrypto.

Thanks.