[Inkscape-user] Trouble to save svg and export to pdf

Hi,

I have a figure with 4 levels and different types of elements on these levels. the important part is a png image where I removed the background to have colour shining through. However I donot succeed in saving the svg file and exporting it to pdf: the png figure is not shown. Do you have any idea what triggers this behaviour? Other similar files are properly saved and exported. Enclosed are two screenshots to show what is shown in inkscape (1) and anywhere else (2), for example in windows explorer which is examplary for Acrobat and anyother program. You will notice that the next figure 127BK is shown properly, demonstrating that with the first figure there is something fishy.

Thanks for your help

Bernhard