I have successfully used digger to convert a .gpx file into a .mca file and load it. I need some help on how to make the image for the custom POI look bigger on the map view. I have tried playing with the scale factor numbers a bit, but I guess I do not understand what they mean or how to adjust them.
There is album.style file in navigator folder. You can edit it using notepad and look for "mark" (I think this manage scale of images from digger/mapexplorer). We also have an editor for editing styles(I do not know if it supports modification of markers)