Hi Lisa,
The issue has gone away, although I am not sure exactly what caused it. I didn't reinstall Express Scribe in the end. My system was having a few other issues, so I gave it a good clean up using AVG PC TuneUp and CCleaner (free/trial versions of both). Between them, this cleared up space on my hard drive (even though I still had plenty of space left) and helped things run more smoothly. Magically, I can use the wireless headphones and the foot pedal together now. I hope that helps you, too.