I previously thought that JB 4.3 update has rectified the wifi crash issue for good. After over a week with 4.3, wifi crash happened today.
The wifi option page was not grey-out, but it would not connect to any network, When I toggled it from "on" to "off" state, it failed to respond. At the end, only a phone reboot could fix it.
Frustrating to say the least.