Can you restart the device now its connected to KoalaSafe wifi.
What happens when you visit http://stackoverflow.com?
If it still doesn't join send us or post here the MAC address of the Chromebook and we will add it.
Also, this is the second Chromebook recently that has had trouble, we are interested in finding out why (our test books connect fine)
What version of ChromeOS is being used? Is it just default settings?