I assume it is the version of GetPopupInfo.exe, 15.0.0.0 which is relevant, it is years old so maybe the problem is resolved. Anyway, the first track 1_swordsofdoom.mp3 on http://www.dsforge.net/doomsword/media/ is identified as free-format. Likely the application miscalculates bitrate to above 320 and concludes freeformat.