WAV file not playing in Audacity 1.2.6 with Vista Home Basic

I jsut installed Audacity 1.2.6 on my new Vista laptop to do some simple sound recording.  I opened a couple of sound files to check playback and when I hit the play button, I heard a quick pop and saw the volume meter jump and that was it.  No playback.  I see the file and waveform.  When I hit shift and play, the timeline marker appears to move along the timeline, but all I get is a constant digital noise.  In the I/O section of Preferences, I have tried both Microsoft Mapper and Speaker/Headphones and Microphone selections, both with the same results.

Any suggestions?

Thanks!