Hello Superdave

                              SBG10 is a gateway which is the combination of modem and router so please let us know are you getting intermittent connection issue on only Wi-Fi or even with direct connection? If the Wi-Fi is dropping you can try changing Wi-Fi channel on the modem interface because if other Wi-Fi sources such as neighboring wireless access points are using the same wireless channel, this may cause intermittent connectivity issues, even if the competing signal is relatively weak. Changing the wireless channel within the  gateway can improve connectivity. so please follow the steps mentioned on the link below to change Wi-Fi channel, After changing Wi-Fi channel as recommended on the link restart the modem then i would request you to monitor the connection for next 24hrs.

                                http://arris.force.com/consumers/articles/General_FAQs/SBG10-Changing-the-Wi-Fi-Channel

Let us know if this helps