I doubt many boats are affected, but Raymarine has issued a bulletin for a bug that "only manifests itself in C-Series Widescreen and G-Series systems that meet ALL 3 of these conditions:
1. There is an external GPS sensor connected via SeaTalk to the display (such as the Raystar 125).
2. The datum is set to something other than WGS 1984.
3. The system has one of these software versions:
-C-Series Widescreen: v1.12 or v1.13
-G-Series GPM400: v2.25"