This should be fairly easy to implement, but if you could put a horizontal scroll bar in the "item" area so it would be possible to read longer filenames (at the moment, I can't see the name of the files that have been processed because the folder name portion pushes the filename off the edge of the visible display area)
The other suggestion I think would be helpful is to put a right click option that allows you to "clear all successful". That way, if someone wanted to rerun only the "unsuccessful" files they could just select that option and hit "start".
An alternative (or perhaps a third suggestion) would be to add a right click option that says "run this file". That way, if you only wanted to run a single item from the list of items, you could do so (once again, that would allow you to rerun "failed" files or to run a quick test before you actually ran a much longer batch of files).
Anyway, thanks for the great app