I did not notice this - iwconfig reports the old essid but
the powermanagement has been switched off. It does not
report the "not ready" state ...

Also, it seemed to me that using iwconfig to turn power
management back on actually did not stop the battery
drain. Only a reboot worked. But I'll have to look at that
more closely to see if it's really true.

I wonder, does anyone else see this behavior?