Testing geotargetting - Anonymous proxies don't work

[Asia_Expat]

In brief, geotargetting is critical to my advertisers. I'm 99 percent sure I've got it right. I've got people sending me screengrabs from the appropriate countries but I need to be sure...

I'm in the UK right now but I have a server in Singapore and a server at our house in Thailand, both of which are set up as VPNs for my own private use. However, even they aren't fooling the geotargetting. I've tried highly anonymous proxies etc etc but the system still knows I'm in the UK.

I'm using OpenX... how is it detecting my location and how can I fool it?

Thanks.

P.S. Already tried posting in the OpenX forum... no reply in a week :-(

[lammert]

First thing which comes in my mind are cookies.
Second, have you tried visiting a browser header checker website when you are connected through a proxy? There may be some headers passing through the proxy which identify your actual location or IP address.

[Asia_Expat]

Thanks for your comments lammert. Indeed, I tried clearing and flushing everything from FF but that didn't work... but clearly I missed something because your above post prompted me to look at cookies again, so I tried a different browser (Chromium) after clearing the entire cache and I can now use a proxy to view the geotargetted adverts...

I wonder why I couldn't get it to work in FF? Strange.