Scan file system based on newest content.
When adding a new album and set Bliss to scan it woud be handy if it either only scanned the new content or start with the most recent changes to the file system so rather than waiting for the whole library to update and then fix non-compliant items they can be done pretty much straight away.
I'm guessing then, you are copying files into your music library, then pressing "rescan"?
You shouldn't have to press rescan. It may take a short time, but the new files should show up in your music library, and only those files will be audited. If that doesn't work it's a bug. Also, the "Play" button needs to be pressed.
In some cases this might not work: e.g. on OS X, if you copy the files into the music library using a different computer it won't work. This is a limitation of the OS X file notification API.