2012-11-15: This turned out to be a completely different issue. Will remain here for historical purpose. In fact, my attempts at solving this issue caused iSCSI outage for other people.

Finally. At least some light after months of “ifdown/ifup…”. I’ve even written the ifreset script to make this not so unpleasant… So, I’m writing this after my laptop started the network during the boot sequence! This is still a workaround but somehow closer to the real issue. Comment out the following line inside /etc/udev/rules.d/85-iupdown.rules:

ACTION=="add", RUN+="/sbin/start-stop-daemon --start --background --pidfile /var/run/network/bogus --startas /sbin/ifup -- --allow auto $env{INTERFACE}"

It turns out that as soon as driver module gets loaded into the kernel, udev starts ifup which is not capable of bringing wpa_supplicant but still marks the interface as up (writing wlan0=wlan0 to the interfaces state list). During the boot sequence ifup is started again but won’t do anything as the interface is already marked as “up”.

Hope this helps at least somehow. I have a PCMCIA device which is never removed though… If you comment that section out, you will not have your network started automatically if you insert your usb card so you will have to restart networking after that. In case your card is not going to be wandering anywhere, this can be pretty safe.