After a reboot no automatic connection to wifi

[Pagemakers]

My wifi works fine until I turn my phone off then on. Then it does not automatically reconnect to the airport wifi network.

This has only happened since ios4 and I can duplicate it on numbers iPhones.

 

[Pagemakers]

If I change from WPA2 to WEP it works but it does not reconnect after a reboot to WPA2