"Analyze Only" causes fragmentation?

[ImUnicke]

So strange as this sounds, it appears MyDefrag is causing huge amounts of fragmentation on my volumes?  Regardless, here are some screenshots.  I first had run Auslogics Disk Defrag on every drive, and everything was all defragmented.  Then I ran the "Analyze Only" default script of MyDefrag and it would tell me many files are fragmented in each of my various drive.  Then I would re-run the defrag in Auslogics and voila, it now sees tons of fragmented files.

As I'm relatively new to MyDefrag, I'd rather not throw the blame that direction but I'm really confused as how an "Analyze Only" seems to cause fragmentation.  Does anyone know why this would happen?

Attachments:
DEFRAG09_Auslogics_MID-MyDefrag_9-12-09.png -- This is the analyze option of Auslogics when the MyDefrag analyze had just started showing fragmentation.
DEFRAG09_Auslogics_POST-MyDefrag_9-12-09.png -- This is the analyze option of Auslogics when the MyDefrag analyze had completed.
DEFRAG09_MyDefrag_POST_AnalyzeOnly_9-12-09.png -- This is the MyDefrag window after the Analyze Only had completed.

EDIT:  To be more specific, upon running the Auslogics defrag, it is showing 2,060 fragmented files on the shown drive.

[jeroen]

So strange as this sounds, it appears MyDefrag is causing huge amounts of fragmentation on my volumes?

MyDefrag keeps a list of files that were unmovable on the previous run (the "MyDefrag.dat" file). It will test if all these files are still unmovable just after analyzing a disk by trying to move the first cluster of each file. If successful then the file is now movable. The test will fragment the files, because only the first cluster is moved. In the next version of MyDefrag it will move the first 50 clusters, so files smaller than 50 clusters will no longer get fragmented by "Analyze Only".

[ImUnicke]

Very interesting   Thanks for the info 

[Kasuha]

o.O Perhaps MyDefrag could move the cluster back if successful...

[Darlis]

I've also suggested this, but Jeroen thinks otherwise:
http://www.mydefrag.com/forum/index.php?topic=2374.msg14390;topicseen#msg14390

@Jeroen: How about a setting like "TestUnmovables(yes/no)". If you would put this in the AnalyzeOnly script, it would really only analyze the disk -> no file movement, no extra fragmentation (This looks bad in the statistics and diskmap, you know )