when does postgresql read from pg_hba.conf ??

Hello, list

from the postgresql documentation I know, that "The pg_hba.conf file is
read on start-up and when the main server process receives a SIGHUP
signal. If you edit the file on an active system, you will need to
signal the server (using pg_ctl reload or kill -HUP) to make it re-read
the file."

But there have been an incident this Saturday that indicates, that these
are not the only triggers for reading pg_hba.conf. One of our clients
edited pg_hba.conf that day (not correctly I must add), but neither
restarted nor reloaded the postgresql (logs below confirm that). Anyway
at some point the system started using the newly edited file causing
some problems. What could cause the pg_hba.conf to be read by postgresql ?

OS: Win XP SP3
DB: Postgresql 8.3

The log (from pg_log):
2010-04-24 13:49:43 EEST LOG: loaded library
"$libdir/plugins/plugin_debugger.dll"
2010-04-24 13:51:07 EEST LOG: loaded library
"$libdir/plugins/plugin_debugger.dll"
2010-04-24 13:52:31 EEST LOG: loaded library
"$libdir/plugins/plugin_debugger.dll"
2010-04-24 13:53:54 EEST LOG: loaded library
"$libdir/plugins/plugin_debugger.dll"
2010-04-24 13:55:22 EEST LOG: loaded library
"$libdir/plugins/plugin_debugger.dll"
2010-04-24 13:56:45 EEST LOG: loaded library
"$libdir/plugins/plugin_debugger.dll"
2010-04-24 13:57:38 EEST LOG: loaded library
"$libdir/plugins/plugin_debugger.dll"
2010-04-24 13:57:38 EEST LOG: invalid IP mask "md5" in file "C:/Program
Files/PostgreSQL/8.3/data/pg_hba.conf" line 72: Unknown host
2010-04-24 13:57:38 EEST FATAL: missing or erroneous pg_hba.conf file
2010-04-24 13:57:38 EEST HINT: See server log for details.
2010-04-24 13:57:46 EEST LOG: loaded library
"$libdir/plugins/plugin_debugger.dll"
2010-04-24 13:57:46 EEST LOG: invalid IP mask "md5" in file "C:/Program
Files/PostgreSQL/8.3/data/pg_hba.conf" line 72: Unknown host
2010-04-24 13:57:46 EEST FATAL: missing or erroneous pg_hba.conf file
2010-04-24 13:57:46 EEST HINT: See server log for details.
2010-04-24 13:58:05 EEST LOG: loaded library
"$libdir/plugins/plugin_debugger.dll"
2010-04-24 13:59:28 EEST LOG: loaded library
"$libdir/plugins/plugin_debugger.dll"
2010-04-24 13:59:58 EEST LOG: loaded library
"$libdir/plugins/plugin_debugger.dll"

--
Julius Tuskenis
Programavimo skyriaus vadovas
UAB nSoft
mob. +37068233050