We develop a tool to print/convert Autodesk Inventor drawings automatically. The conversion options include conversion to PDF and TIFF and we use the Amyuni PDF Converter for this.
Problem:
When the Inventor Drawings include shaded views ( = colored image of the model, as opposed to the standard representation where the model is displayed as a wireframe) the PDF documents created with Amyuni converter software contain several image defects. The upload attachment function of this forum doesn't accept my screenshots for whatever reason so i uploaded them to our ftp server:
The first screenshot is from a very simple Inventor drawing sample. The upper half is from a drawing that was converted to PDF via Amyuni driver using the standard settings. The lower half is the same document, but this time printed in grayscale. As you can see, the PDF converter replaces some sections of the image with plain dark gray squares.

The second screenshot displays another weakness of the converted PDFs. Sometimes the converted drawings contain white "gridlines" that don't belong in the drawing, like the three horizontal white lines in this section view:

I guess the amyuni converter splits bitmaps into small sections that are separately converted and then assembled in the resulting PDF, or something similar. obviously this system doesn't work very well in our case as some of these image pieces are corrupted (as in the first screenshot where some squares are simply dark gray). i think the second problem with the "gridlines" is caused by this as well. seems that the individually converted image pieces are not always assembled correctly, the white lines probably are a result of the pieces not correctly aligned?
so the question is: Is there any setting, workaround, trick, whatever to avoid these problems? As it stands now our product can not handle shaded views in inventor because the Amyuni converter sometimes produces results as seen in the 2 screenshots. I posted a similar question about one year ago but there was no solution found, so i try it again now as one of our customers reported this problem to us and we still haven't found a way to solve the problem. Is there some setting that tells the Amyuni driver to use a different conversion mode to avoid this problem? We currently use the Amyuni PDF Converter version 3.01a in our product and tested the newer 3.03 build last week, but the behaviour is still the same. Didn't find any new options to try out so far, so if there were any significant changes we may have missed please tell us.