Problems in China

[Bryan]

Ok, I've done a ton of reading and know all about "The Great Firewall
of
China". However I still need a definitive answer on this because it
just
doesn't make sense.

We have a domain which has worked globally for the last 5+ years. Last
Thursday we started getting reports from our customers in China that
they
could no access our website, nor could they send email to us. They ARE
receiving our email.

Querying a couple Chinese dns servers confirmed that they were not
resolving
our host name.

Our domain had been serviced by mydyndns.org for several years without
any
problems. Guessing that China may have a beef against ONE of THEIR
customers, and blocked THIER dns we went ahead and changed over to our
own
primary and our providers secondary. Still no go.

Here is some data from after the change, hopefully someone can help me
track
this down.

I'm querying a single Chinese dns server here but it can be replicated
among
others. It mostly seems to be in mainland China, Hong Kong doesn't have
a
problem resolving our name.

Here is an initial dig:
; <<>> DiG 8.3 <<>> @202.106.148.1 usbid.com
; (1 server found)
;; res options: init recurs defnam dnsrch
;; got answer:
;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 6
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0
;; QUERY SECTION:
;;      usbid.com, type = A, class = IN

;; Total query time: 4000 msec
;; FROM: W008BDOL to SERVER: 202.106.148.1
;; WHEN: Tue Jan 25 10:28:31 2005
;; MSG SIZE  sent: 27  rcvd: 27

Subsequent digs are different and look like this:
; <<>> DiG 8.3 <<>> @202.106.148.1 usbid.com
; (1 server found)
;; res options: init recurs defnam dnsrch
;; res_nsend to server 202.106.148.1: Unknown error
Thanks in advance!