I'm also getting the same 404 errors across their site in various locations.
I just got the Obi 200 to replace the 100. I've had it plugged in for 24 hours now, but still can't get past the 404 mess on their site to setup GV.
Specifically, when I attempt to link a Google Voice account, I go through most of the steps. I get past the popup window asking me to link my Google account to Obitalk. The next popup shows an Obitalk page that asks me to confirm the Google account I'm going to use on Obitalk. I hit confirm, then get the 404. If I back out of the 404 error and get to my dashboard, GV actually does show up, but with a status of "Service Not Configured" that never changes.
If I go to delete the GV entry on the dashboard, that leads me to a 404 error, too. But when I back out of it and get to the dashboard, it does appear to be gone.
I'm 99% sure I'm doing all of this correctly. I've even factory reset my router to remove any possibility that I had a bad setting on there causing a problem. I sure hope someone over there gets their act together and fixes these 404 errors so we can configure our devices. I didn't spend $50 for a box to flash green lights at me.