Finally solved. Here is the contents of the wirless.prefs file in sys:prefs/env-archive/sys/ folder:

update_config=1

network={
scan_ssid=1
ssid="my hidden ssid"
psk="my wpa password"
}


The laptop now finds my home network on boot.



The unofficial knowledgebase is now updated with the correct fix.
http://bettyboopdatabase.0usa.com/mos/mos.html



[ Edited by bash64 18.07.2013 - 01:11 ]