I have have experienced this for while and I thought I would mention it. If I add a song or some other slide with a plain black back ground and white text and select a new media background the text stays white. I would think it would change to match the new media background preset font color.
There may be a quick way to access the preset font color but I don't know how to get to it without adding a new slide from the media background selection finding the font color for that background and coping to my slides I have create already. Should the font color change to match the new media background I set for a particular slide?
Keep up the great work,
Troy