I sort alot of my music and movie library by the date I added it to the collection. I really like the ability to Google search for and add cover art right inside the web interface, it's pretty slick. However, each time I add cover art, the folder where the art was placed is moved at the top of the 'Newest' pile.
Based on how I've seen the index work, I'm assuming it scans the folder for the file with the most recent created date and sets that as the Created Date for the media in Subsonic.
For example, if I grab cover art for an album that I added on 1/4/2009, the next search index update will place this media at the top of the 'Newest' list. However, the media isn't really new but it has been updated.
Since I know other users prefer one over the other, I'm requesting that an option be added to define 'Newest' as either the modified date or the created date value.