DNS cache poisoning attacks

[EL MAAYATI Afaf]

Hello,
            As recommended, I've upgraded my DNS server to the version BIND 9.5.1b1 <http://www.isc.org/sw/bind/view?release=9.5.1b1> . But I still have the message indicating that my server is still vulnerable 
 
# dig @192.168.2.3 +short porttest.dns-oarc.net txt
Porttest.y.x.w.v.u.t.s.r.q.p.o.n.m.l.k.j.i.h.g.f.e.d.c.b.a.pt.dns-oarc.net.
"192.168.2.3 is POOR: 26 queries in 6.4 seconds from 1 ports with std dev 0"
 
Is there anything that I've missed?
 
 
Best Regards,