We have recently installed a new website for a client. They changed tags to our ISP and everything seemed to be OK after 24 hours when the DNS changes had propogated.
You can see the new website from anywhere - except in their own premises.
All the PCs in the premises are showing their old website.
If they use a mobile phone and 3G from within their premises they get the new website. If they use a wireless connection on their phones they get the old website.
I have got them to turn their PCs off and on, the router off and on, Proess F5, ctrl plus F5 on each PC, tried different browsers. Nothing has worked yet and I'm going to go there just now.
They have a server which they are going to restart at lunchtime.
Any further suggestions welcome.