Yesterday and today I've encountered what I think are DNS problems.

Some web pages come up fine in my browser but others sit there for a while with "Looking up hostname for ..." in the browser status bar and then say "Could not locate remote server".  If I refresh the page then sometimes I connect and sometimes I don't, after 5 or so tries I can usually connect.  My FTP program kept telling me it couldn't find the server I was trying to reach, but finally on the 10th attempt it worked.  It took me 5 or 6 attempts before Spybot could update itself.  What I'm trying to say is that this isn't limited to my browser, it's all my internet connected software.

Also it's not on just one PC, but on three different PC's on my LAN.

The router is set to obtain the DNS servers automatically.  The router says that currently the primary is 203.109.129.67 and the secondary is 203.109.129.68.  PC's are set to use the router for DNS.

I've rebooted the router in case it had got itself in a tangle.

Using nslookup to test a site using the Vodafone supplied DNS server I get the following:

C:\Documents and Settings\Murray>nslookup -debug www.aweb4u.co.nz. 203.109.129.67
------------
Got answer:
HEADER:
opcode = QUERY, id = 1, rcode = NOERROR
header flags: response, want recursion, recursion avail.
questions = 1, answers = 1, authority records = 2, additional = 2

QUESTIONS:
67.129.109.203.in-addr.arpa, type = PTR, class = IN
ANSWERS:
-> 67.129.109.203.in-addr.arpa
name = ns1.ihug.co.nz
ttl = 12903 (3 hours 35 mins 3 secs)
AUTHORITY RECORDS:
-> 129.109.203.in-addr.arpa
nameserver = core.ns1.vf.net.nz
ttl = 14476 (4 hours 1 min 16 secs)
-> 129.109.203.in-addr.arpa
nameserver = core.ns2.vf.net.nz
ttl = 14476 (4 hours 1 min 16 secs)
ADDITIONAL RECORDS:
-> core.ns1.vf.net.nz
internet address = 203.109.134.2
ttl = 36108 (10 hours 1 min 48 secs)
-> core.ns2.vf.net.nz
internet address = 203.109.135.2
ttl = 36108 (10 hours 1 min 48 secs)

------------
Server: ns1.ihug.co.nz
Address: 203.109.129.67

DNS request timed out.
timeout was 2 seconds.
timeout (2 secs)
*** Request to ns1.ihug.co.nz timed-out

Doing the same thing but using Google's DNS server I get the following:

C:\Documents and Settings\Murray>nslookup -debug www.aweb4u.co.nz. 8.8.8.8
------------
Got answer:
HEADER:
opcode = QUERY, id = 1, rcode = NOERROR
header flags: response, want recursion, recursion avail.
questions = 1, answers = 1, authority records = 0, additional = 0

QUESTIONS:
8.8.8.8.in-addr.arpa, type = PTR, class = IN
ANSWERS:
-> 8.8.8.8.in-addr.arpa
name = google-public-dns-a.google.com
ttl = 43198 (11 hours 59 mins 58 secs)

------------
Server: google-public-dns-a.google.com
Address: 8.8.8.8

------------
Got answer:
HEADER:
opcode = QUERY, id = 2, rcode = NOERROR
header flags: response, want recursion, recursion avail.
questions = 1, answers = 2, authority records = 0, additional = 0

QUESTIONS:
www.aweb4u.co.nz, type = A, class = IN
ANSWERS:
-> www.aweb4u.co.nz
canonical name = www3.iserve.net.nz
ttl = 34945 (9 hours 42 mins 25 secs)
-> www3.iserve.net.nz
internet address = 202.191.42.30
ttl = 2051 (34 mins 11 secs)

------------
Non-authoritative answer:
Name: www3.iserve.net.nz
Address: 202.191.42.30
Aliases: www.aweb4u.co.nz

From the little I know about DNS it looks to me like Vodafone's DNS failed to look up the domain name while Google's worked ok.

Can anyone offer any suggestions for anything else I can try to rule out problems at my end?

I've looked on Vodafone's forum but they're not reporting any problems and no one is complaining there.  I'm in Glenfield on Auckland's North Shore.