make clean fails in /usr/src

[Raphael Marmier <raphael@xxxxxxxxxxx>]

I get this when run make clean in /usr/src (current):

it works fo a while, then:

===> usr.sbin/named
rm -f  named aclconf.o client.o config.o control.o controlconf.o 
interfacemgr.o listenlist.o log.o logconf.o main.o notify.o query.o 
server.o sortlist.o tkeyconf.o tsigconf.o update.o xfrout.o zoneconf.o 
lwaddr.o lwresd.o lwdclient.o lwderror.o lwdgabn.o lwdgnba.o lwdgrbn.o 
lwdnoop.o lwsearch.o os.o named.8.gz nsupdate.8.gz named.8.cat.gz 
nsupdate.8.cat.gz
rm: named: is a directory
*** Error code 1

Stop in /usr/src/usr.sbin/named.
*** Error code 1

Stop in /usr/src/usr.sbin.
*** Error code 1

Stop in /usr/src.
*** Error code 1

Stop in /usr/src.

I know I just have to remove obj/*

The system is running STABLE of about 10 days ago and the source tree 
from HEAD.
bug?

regards

Raphael