Well, for me at least.
I was in the process of dumping iTunes 7 and exploring the folder system created by iTunes 7. One of the items in that folder was an alias that pointed back to the music folder. Something like this:
I ran firefly last night just to see what it would do with a large chuck of time. This morning the log said that it had started and was serving 500000 songs and that it took 8000 seconds to complete the scan. After dumping the alias I re-installed firefly (just in case) and re-scanned. This time the log said 2500 songs scanned in 60 seconds.