In our newsroom environment, staff prefers to have MP3s from various download sources open directly in an outside program's window (in this case Goldwave is the preferred program). That being said, with the newer versions (28 and 29 specifically) the behavior of the program has changed so that MP3s are opening in a separate browser tab, regardless of the preferences in the "Applications" window of the Options as well as the program defaults within Windows. Previous adjustments made to about:config media.windows-media-foundation.enabled and setting to "False" no longer solve this issue.