something else i've just discovered:
when i was connected to a wireless lan network before hibernate, the whole system freezed after resume (no chance to switch to console by CTRL + ALT + 1). when i disabled wlan before hibernating i was able to resume but as soon as a reactivated wlan the system was freezing up.
after a bit of searching i came across this askubuntu-discussion and tried the described solution of creating a file (i named it '20_wlan-hibernate-fix' in /etc/pm/config.d with the content
EDIT: i first thought this would work but soon discovered that the freezing still occurs especially when the available wireless networks change in the meantime (other location).
SUSPEND_MODULES="$SUSPEND_MODULES iwlagn xhci-hcd"
next thing i'll try is the script described in this post and let you know how things turn out with this one...
EDIT2: unfortunately this also did not work =( same freezeup as before. basically the script unbinds and rebinds the device found at /sys/bus/pci/drivers/ehci_hcd and /sys/bus/pci/drivers/xhci_hcd but since in the ase of the AO722 there is no xhci-device but a ohci device i'll give it another shot with this one...
i wonder if anybody else came across this issue? anybody who can hibernate why connected by wireless lan without a system-freeze on resume without a fix like i just described?