Has anyone encountered this problem? I have a RL70C Radar/Chartplotter hooked up with a GPS 300 through sea talk. I have recently experienced difficulties with the ability to zoom into and out of my C-Map. I often only get Half a screen of information or even NO CHART DATA messages. I have tried 3 different C-Map data chips and they all seem to have the same problem. This is a consistant problem (not intermittent) and I have to do a complete system reset in order to restore the information. The unit is only about 5 months old. Thanks scottb@thepostshop.com