Vista machines DOSing our bind servers

[Kirsten Petersen]

Has anyone else seen this issue where Vista machines slam the name servers 
with repeated requests for the same lookup?  Yesterday, both of our name 
servers were taken out of commission by a pair of Vista workstations on 
our network that were each pushing almost 10Mb in DNS requests.  A tcpdump 
at the time showed that they were asking repeatedly for the same AAAA 
record.

This has happened about 4 times to us in the past 3 weeks.  Each time, 
the machines were asking for different domain names, totally unrelated.
  So, I don't believe there is anything special about the record itself.
  The machines have been scanned for viruses and malware, of course, and 
came up clean.  The owners of the machines were not even present when the 
incident occurred.

I have read through this thread on Educause:
http://listserv.educause.edu/cgi-bin/wa.exe?A2=ind07&L=netman&D=0&T=0&P=27697