Thanks Philip,
I'm using bridge mode for the wireless ap which from the looks of it gets the i.p from DHCP from the internal lan.
Looking at the DHCP settings I can see that DNS is set to proxy to upstream DNS.I suspect this might be the issue as we have our own DNS servers locally that we use to manage all our internal DNS.
I'm going to try changing this to our internal DNS servers, however I'm scared to do this remotely so will hang fire until I'm in the office in case I lose access.
Thanks for the advice, once I confirm this is this issue ill set your reply as the solution.
Very much appreciated mate, thanks again.