could you post screen shot of your network config from you VU. Also you mentioned "lastest openpli" but your signature says 7.3. What version are you running ?
Also, how does your VU connects to your modem/router, Wifi or LAN cable ? what is the LAN IP address of your modem/router ?
Therefore no reason that network settings are screwed-up after a restart, except due to a major software bug/error and/or a HW failure (hence the question on how is the VU connected to modem/router).
Finally, when you say "press red button to start the network wizard", if I look at the link you provided, it seems you need to hit the OK button to start the wizard, noit the red button !