I was playing around tonight with some stuff and happened to have PathFinder open while I was downloading a fairly large file. I noticed that while the file was coming down, it showed up in the Downloads folder, but the Date Added field was blank.
What I'm suggesting as a tip is that if you want to start processing a file only after it is completely downloaded,* set the first condition to be (Date Added)<is not blank>. I'll do a post on my blog with pictures and stuff, but I'm pretty sure you know what I'm talking about.
* This also works with files that are being encoded/decoded. I ran a file through ffmpeg and it didn't fill in the Date Added field until the process was complete.
Phaedra Deepsky
veganswithtypewriters.com