Once you hit "scan" it slows down Firefox to an absolute crawl (clicks take very long to register) for at least a quarter hour before eventually crashing it totally. Restarting Firefox & then hitting "scan" in the extension, again froze Firefox.
Updated this in 2.7.51. It was causes by zipping and embedding files, asking A LOT of ram from the browser. Now, after each zipped song, we clear the state and build a new zip. This just uses 100mb ram max and will not increase anymore.
