Thank you for your fast response.
I immediatelly tested the same samples with tif-format.
You are right, the output resolution is now correct.
Regards

My input files have 240 dpi but the output file is always fixed to 72dpi.
I have set the output resolution to 300 dpi in the configuration window, but there is no reaction.
I found several requests on this topic (already from 2009) but no answer.
I still use the demo-version 5.1.29 for evaluation ...