Files are left fragmented

Hi.

I've noticed that files are left with fragments. Defragging one file only comes back with a message that nothing was done. The file in question is a video file of about 1Gb size. Hard drive is 80 Gigs with 21 Gigs free.

I also see that files that are not fragmented are left scattered around and not packed in order to leave as much free space as possible.

I have read the documentation and I have seen the different suggestions on how to defrag one file only but it does not do what it's supposed to do.

I just want to understand the nuts and bolts of Defraggler so if someone can explain why the program does as it does, I'll be happy.

Thank you

/Leslie

Perhaps a screen shot would give something to discuss and even suggest