[mkgmap-dev] Change in Garmin IMG format?

I'm not sure if my message is relevant to this discussion list or not. I own an Edge 1030 and I use mkgmap to make custom maps for it. Recently Garmin provided a firmware update for the 1030 (ver. 12.0).  After I installed it none of my custom POI symbols appear on the map.  In addition, the default Garmin POI symbols have been updated by Garmin.  All my custom line and polygon symbols still display.  I saw comments from some users in the Garmin forums that TOPO maps will no longer work with the firmware update either. It appears Garmin may have revised the format of their IMG files, if only slightly.  I don't know if this affects all Garmin models or only certain ones. Mark