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(at)yahoo(dot)co(dot)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.