BUG #5660: Can't start db service if specify effective_io_concurrency

The following bug has been logged online:

Bug reference:      5660
Logged by:          Mikio
Email address:      tkbysh2000@yahoo.co.jp
PostgreSQL version: 9.0 RC1
Operating system:   Windows XP SP3 Japanese
Description:        Can't start db service if specify
effective_io_concurrency
Details:

I'm using postgresql 9.0 rc1, and I specified 10 for
effective_io_concurrency in postgresql.conf.
I restarted postgresql windows service, but the service didn't start.
I looked a log file in pg_log directory, but no relative entries.
I looked windows event viewer, I found an event from PostgreSQL, and it was
below.(The characters in the message were broken.)

>FATAL:  p[^"effective_io_concurrency"ύXł܂

I changed the value from 10 to 1, but the symptom was same.
I commented the line out like as default, the service started up successful.