BUG #5100: Help me!!I want cause : "invalid page header in block xxxx", i need support to repair and avert

The following bug has been logged online:

Bug reference: 5100
Logged by: Viet Duc
Email address: nvduc(at)ifisolution(dot)com
PostgreSQL version: 8.3.1
Operating system: Window xp
Description: Help me!!I want cause : "invalid page header in block
xxxx",i need support to repair and avert
Details:

Help me!!I want cause : "invalid page header in block xxxx",i need support
to repair and avert.
------------------------------------------
2009-10-03 16:08:59 ICT LOG: loaded library
"$libdir/plugins/plugin_debugger.dll"
2009-10-03 16:08:59 ICT LOG: database system was interrupted; last known up
at 2009-10-03 16:04:18 ICT
2009-10-03 16:08:59 ICT FATAL: the database system is starting up
2009-10-03 16:08:59 ICT LOG: database system was not properly shut down;
automatic recovery in progress
2009-10-03 16:08:59 ICT LOG: redo starts at 2/DC213F0
2009-10-03 16:09:00 ICT LOG: loaded library
"$libdir/plugins/plugin_debugger.dll"
2009-10-03 16:09:00 ICT FATAL: the database system is starting up
2009-10-03 16:09:01 ICT LOG: loaded library
"$libdir/plugins/plugin_debugger.dll"
2009-10-03 16:09:01 ICT FATAL: the database system is starting up
2009-10-03 16:09:02 ICT LOG: record with zero length at 2/DC2FB38
2009-10-03 16:09:02 ICT LOG: redo done at 2/DC2FB08
2009-10-03 16:09:02 ICT LOG: last completed transaction was at log time
2009-10-03 16:04:36.562+07
2009-10-03 16:09:02 ICT LOG: loaded library
"$libdir/plugins/plugin_debugger.dll"
2009-10-03 16:09:02 ICT FATAL: the database system is starting up
2009-10-03 16:09:04 ICT LOG: loaded library
"$libdir/plugins/plugin_debugger.dll"
2009-10-03 16:09:04 ICT FATAL: the database system is starting up
2009-10-03 16:09:05 ICT LOG: loaded library
"$libdir/plugins/plugin_debugger.dll"
2009-10-03 16:09:05 ICT FATAL: the database system is starting up
2009-10-03 16:09:06 ICT LOG: loaded library
"$libdir/plugins/plugin_debugger.dll"
2009-10-03 16:09:06 ICT FATAL: the database system is starting up
2009-10-03 16:09:08 ICT LOG: loaded library
"$libdir/plugins/plugin_debugger.dll"
2009-10-03 16:09:08 ICT FATAL: the database system is starting up
2009-10-03 16:09:08 ICT LOG: database system is ready to accept
connections
2009-10-03 16:09:09 ICT LOG: autovacuum launcher started
2009-10-03 16:09:09 ICT LOG: loaded library
"$libdir/plugins/plugin_debugger.dll"
2009-10-03 16:09:46 ICT LOG: loaded library
"$libdir/plugins/plugin_debugger.dll"
2009-10-03 16:10:07 ICT LOG: loaded library
"$libdir/plugins/plugin_debugger.dll"
2009-10-03 16:10:08 ICT LOG: loaded library
"$libdir/plugins/plugin_debugger.dll"
2009-10-03 16:10:08 ICT LOG: loaded library
"$libdir/plugins/plugin_debugger.dll"
2009-10-03 16:10:09 ICT LOG: loaded library
"$libdir/plugins/plugin_debugger.dll"
2009-10-03 16:10:12 ICT LOG: loaded library
"$libdir/plugins/plugin_debugger.dll"
2009-10-03 16:10:12 ICT LOG: loaded library
"$libdir/plugins/plugin_debugger.dll"
2009-10-03 16:10:28 ICT ERROR: invalid page header in block 20 of relation
"LOG"