!! Good news !!
The bug has been removed and a new version of emPolygonizer4 is available. It is version 4.01 and these are the changes:
Version 4.0 crashed with Softimage 2013 SP1. After a bit of research it appeared that -oh what a surprise!- the damn clusters and cluster properties were once again responsable. After even more research I decided to remove those clusters ENTIRELY and FOREVER from emPolygonizer, because they have been a constant source of problems since the beginning.
All the user data (motion vectors, user normals, UVWs and vertex colors) are now available as beautiful ICE data!
That means: a.) no more crashes, b.) more flexibility for the user and c.) better overall performance.
He, he, I guess that bug did more good than harm
Anyway, the addon and the demo scenes have been updated and tested under Windows 64 bit / Linux 64 bit and with Softimage 2012 SAP and Softimage 2013 SP1.
You can get the latest version here on the emPolygonizer4 web page
Should anybody encounter any further issues please let me know!
PS: in a few hours there will also be a quick "walk-through" video tutorial on vimeo. I'll keep you posted.