My Beneteau 37 is equipped with Simrad units using the SimNet system. The NSS8 is the center of the system and communicates with the Auto Pilot, IS20 wind and Speed and depth. The VHF is the R35. When working all units report accurate information and Auto Pilot works great. The GPS info stops and Auto Pilot stops working. Position and SOG is still reported on the NSS but SOG stops on IS20 , also the position on The VHF is gone. This happens at least once in a 5 hour sail. Charts and every thing continues to work on the NSS. There it is, Has anyone had a similar problem?