I have now tried 2 different VPN providers the first was overplay.net that provided good suport but the bandwidth when measured between NZ and the UK was nornally around 300K (tested through speedtest website). They seemed unable to find a solution despite trying a number of different config changes. However sppeds were around 1Mb in the morning.
I then moved to BlackVPN. These guys provide better speeds and I can happily sit watching iplayer till about 8pm NZ time, when the speeds really drop and the player starts buffering every 5 or so seconds - making it unwatchable.
By testing my Vodafone broadband bandwidth on speedtest I can see that even after 8pm my bandwith is around 3Mbits per second - which should be ample. However going through blackvpn it drops to 0.22Mb/sec
Now it has been suggested that I go to a torrent - there is one that has a number of uk shows, the name escapes me at present. Anyway does anyone have a working VPN connection to stream the iplayer in the NZ evening.