Derek81 & Alan_B: thanks for your answers, but that doesn't fit to my problem ... all that is known and understood
I think it is difficult to describe my problem with understandable words ... and I guess the question can only be answered by a developer
Starting a defrag I saw after the analyzation that there are less than 10 fragmented files, some minutes later the drive-map showns lots of yellow squares (yes, that are frgaments that are read) and one big green bar (that's the target where the defragmented file was written to)
This was shown for more than 1 Minute because it was a big file.
The shown file name In the Status section was Outlook.pst ... but this file was not in the list of files to be defragged (Tab File list)
I think there are two alternatives:
1. The yellow squares showed the fragments of Outlook.pst ... but than this file was missed in the file list ----> Bug!
2. the yellow squares belongs to one of the files in the file list ... than the shown file name ist wrong, maybe it shows the not-fragmented file that was last recently moved for free space defragmentation ---> minor flaw