Voice memo speaker icon not responding to touch

Boy, I wish there was more support for this app. I use it multiple times a day. The article "Record Voice Memos on your iPhone and iPod touch" doesn't even mention the speaker icon in the upper right of the app screen, that lets you listen to your recorded memos "publicly" (via the speaker) or privately (via the earpiece of the phone).

But, today, mine is suddenly not responding. The rest of the screen responds fine - but I cannot turn off the speaker, and I have memos I need to listen to that I do not want others to hear.

I've restarted the app to no avail.

Apple - please provide good support for all of the apps you make us addicted to!