AlexVallat - 2011-01-20

AAD does not delete settings under any circumstances except for uninstallation. Something else on your system must be deleting the settings files, perhaps some regularly scheduled clean-up utility or tool?

The settings files are stored in %LOCALAPPDATA%\AlbumArtDownloader (on Vista, that resolves to C:\Users\<username>\AppData\Local\AlbumArtDownloader) - if that folder or the files in it are deleted, the AAD settings will be gone.