This installation worked fine till a couple of days ago....
Installation is a Dlink ADSL modem followed by a TP-Link wireless router.
ADSL is working okay from checking the status page - can ping the DNS server at the ISP from inside the Dlink - very low latency and no missing pings.
Have checked this using two diferent PC's ( Win 7 & XP ) with similar results. The PC is given an IP address by the DHCP server in either the Modem or Router. The same result occurs with the PC plugged into the Modem or Router.
Access of the ISP own pages works fine ( 99% of time ). Some other sites apart from the ISP's work if you add a second DNS address into the Router / Modem DNS or PC ( IP address set up page ) from a different ISP !!
Google.co.nz works but Vodafone.co.nz does not - you get the "Google auto-type results" as expected. However, accessing the pages from the Google search not all pages are found / accessable - get a time out / not available message. ( suspect the pages that fail are those hosted off shore )
Windows dianostics when the page lookup fails results in an message saying Windows doesn't know the problem - doesn't fail with an DNS error message.
Have tried resetting the DNS cache via IPconfig / fixed IP & DNS address in the PC's ( and Router & Modem ) - no change. Have done the usual power resets of all the bits.
Any ideas of what to try next would be cool