Another duplicate mp3 finder is MusicMagicMixer. I liked this one for speed and simple UI. On launching the application you will be provided with a dialog to select the media you like to scan.
After selecting the directory containing the media it will start scanning the files.
And once that is done the application will start processing the files to create audio fingerprints immediately.
The good thing is that the processing is very fast. In about 20 minutes it was able to finish processing all of the 578 files. However the bad news is that it is not as good as DuMP3 when finding duplicates. It found none from the 578 files.
So you either have a fast but not accurate software or accurate but slow software. The choice is yours :). But for me I still like the MusicMagicMixer. It did find duplicates in the previous run which I deleted and so now it is showing empty duplicates. And then DuMP3 could find a few more. I don't know if there is a better software that will find all the duplicates much faster. The search continues...