I Read this sollution elsewhere on these forums and found that this worked for me.
However, the "load" time in Safari is not as fast as it used to be. Might be due to some router setting.
For all the Dutch users that have a KPN Experiabox router:
1) go to http://192.168.2.254
2) Username: KPN Password: leave empty (You might have changed this yourself)
3) Go to Network (at the top)
4) Go to WLAN (at the left)
5) Set as follows:
Enable WLAN: Enable
Mode: IEEE 802.11g Only
Transmitting power: 100%
Enable WMM QoS: Disable
This fixed my wifi problems. Good luck