After updating my iPhone 3GS to iOS6, when I'm on WIFI the network connection appears terribly slow. Loading a webpage in Safari takes ages and opening the update tab in the App store seems to keep loading forever. When I turn off WIFI and try the same on a 3G network, it all is responding a lot faster.
I've checked the WIFI connection itself, and from my laptop that appears all fine. Before the update to iOS6, my iPhone was working fine on that same WIFI connection. What can I do?