happens to me aswell 4.0.1-4.1 jailbreak or not... I switch between 3-5 wifizones just at work, had to remove all but the wpa/2 logins
still happens a few times per week, the only major problem I have with the phone
I have spoken with applesupport and my operator (Telia SE), I have access to "surfzones"... basically wifi at cafés, gasstations etc, but I cant use it cuz its web-login and next time I get to wpa a reboot is required 😡
all answers from support is to turn wifi off when leaving a wifizone, and on again at another...