Not sure why, Daniel, but it seems I'm your nemesis

AHAHAH [:))]
Please check the cpu usage using the task manager while exporting to svg.
I suspect that compressing that image could be too heavy for the compression algorithm.
I was expecting there might be problems, so I figured out a way to change the default settings without rebuilding the plugin. You could try to decrease the compression level by starting sh3d with a java property named png.compression,it accepts integer values in range 0-9 (the default is 9).