Bug? could not remove shared memory segment

Hi,

When I shut down the standby server and then the master server in that order,
I found that the master server emit the following message.

LOG:  XX000: could not remove shared memory segment
"/PostgreSQL.1804289383": Invalid argument
LOCATION:  dsm_impl_posix, dsm_impl.c:269

Is this intentional message or a bug?

$ uname -a
Darwin test.local 11.4.2 Darwin Kernel Version 11.4.2: Thu Aug 23
16:25:48 PDT 2012; root:xnu-1699.32.7~1/RELEASE_X86_64 x86_64

I used the latest version of the source code in the git master.

Regards,

-- 
Fujii Masao