Thanks for your hint, but replacing the spaces with %20 does not work as well.
By the way, I discovered a strange situation. I can not read the files inside a folder which contains spaces in the folder name, but I can read out file names which contain spaces (as long as these files are located in folders without spaces).
The same behavior I have by listing directories. If I sent a FTP.List command to a directory which contains no spaces it lists all sub directories INCLUDING the folders which contain spaces.
Only the direct FTP.List command to the path which includes spaces does not work.
Regards,
hennemarc