pkg_install problem

I installed NetBSD/cobalt 5.1 from the install CD and noticed that the 
version of pkg_install included is incorrect (old) which prevents access 
to the nifty pre-compiled binary packages collection.  To fix this, I 
downloaded the correct pkg_install package (here: 
ftp://ftp.netbsd.org/pub/pkgsrc/packages/NetBSD/cobalt/5.1/pkgtools/pkg_install-20110215.tgz), 
ungzipped and untarred it and copied the correct binaries over the 
originals in /sbin.   After that, using pkgsrc was a snap.

Has anyone else seen this?