Did you set up your router according to the directions? Do you have a wireless protocol other than WPA Enterprise or WPA2 Enterprise. Kobo will not work with either of those. Depending on how your router is set-up , you may need to add your MAC address and/or make sure that your Vox IP address is within the range specified in your router.
Here is the Kobo help page on setting up the Vox with a router:
http://kobo.intelliresponse.com/inde...%20Kobo%20Vox?