How about when your ISP forces u to use their proxy, and their proxy goes down. So then you spend hours trying to figure out why the combination of routers in the network has stopped working, and no computers on the network can surf the web, but email can be checked and P2P works fine.
You call the ISP and then they tell you it's a configuration problem with MY network despite after resetting everything, no changed settings, it still doesn't work.
Disable the proxy in IE and I can surf 1/2 the web
I can't even see the cdfreaks news page!
I can surf the forums though WTF?
Mysteriously 2 days later everything starts working again.......
I hate clear-proxies.