The remote host is missing an update to bind9 announced via advisory DSA 1341-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%201341-1

Amit Klein discovered that the BIND name server generates predictable DNS query IDs, which may lead to cache poisoning attacks. An update for the oldstable distribution (sarge) is in preparation. It will be released soon. For the stable distribution (etch) this problem has been fixed in version 9.3.4-2etch1. An update for mips is not yet available, it will be released soon. For the unstable distribution (sid) this problem will be fixed soon. We recommend that you upgrade your BIND packages.