No Sound when playing imported mp3

(audacity 2.0.6, Windows Vista Home Premium Service Pak 2)

I can’t get any sound when I play mp3 files (the only file type I have tried). This used to work the last time I used Audacity which was many months ago. In desperation, I removed and re-downloaded Audacity and it behaves the same way:

The waveform is displayed and when I click the “play” button, the location cursor moves through the waveform as it should during playback. The meter displays left and right channel amplitude bouncing around as expected. But no sound is produced. The default playback device is set to “speakers” on my computer and no USB devices are connected. Other applications that produce sound through the speakers work fine.

I’m most appreciative of any help you can provide!

What options do you have for the playback device in the device toolbar, and which option is selected?