How does SmartDefrag determine "recent used files" to defrag

[DavidOfMA]

I have been running SmartDefrag with all the auto options checked for a few days, and I don't see any evidence that it is actually defragging anything. The files I frequently use remain fragmented, even if I've left the computer idle for several hours. I have all options checked, in the AutoDefrag dialog box. I'm particularly interested in having it defrag my image and image database files, which tend to get fragmented fairly quickly.

Thanks,
- David