I have the MR3420 for a week now. Been having strange issues the first few days , the lights were on but no connectivity to the router, a power cycle fixed that. I then had a few issues where it would show connected but no internet traffic would work. When I plugged the modem in directly in the laptop it would work however back in the router still not working. Switched off the router for about 10 minutes and afterwards is started working correctly. I also had an issue where i disconnected the 3g in the router web interface after which the interface would go all weird and no connection. Power cycle fixed that. Last 3 days i've set the router to connect on demand only had an issue once, so far so good. Routers do seem flaky after day or 2 of operation. i have the latest firmware.