Howdy,
Using UI6 (which is what came on it) with firmware 1.6.641 (latest, according to it)
Setup -> Unit Settings -> Allow only secure access: No
Its pretty consistent:
1) Get Vera3 working normally with internet connected via local IP, login (works fine) and log out
2) Disconnect the internet (i.e. pull plug on cable modem)
3) Within 2-5 minutes, Vera3 WAN light start blinking quickly (which I think means -- help, no internet)
4) Point browser at Vera3 IP
5) Login screen comes up, try to login
6) Get about a 20 second delay, then popup with "Login Failed".
7) Plug internet back in, wait until Vera3 sees it and stops blinking its WAN light

Point web browser at same local IP I've been using
9) Login works fine.
I've repeated the above steps at least 4 times now and the results are always the same.
I'm a bit surprised it falls down so quickly without internet access.
Gerry