Audio comes from only one channel, & panning doesn't work.

I have a project with two wave files that are synced with the video in my timeline, each on its own track.
I have one audio track panned hard right, and the other hard left. When playing the timeline, all audio for both tracks comes out of the left channel.
If I double-click an audio event in the timeline to put it in the source viewer and play it, it comes out of both speakers centered.
I tried dragging a previously unused audio file into the timeline, creating a new audio track; it too played only out of the left channel.
This is beta 6.
Anyone else see this?
I have one audio track panned hard right, and the other hard left. When playing the timeline, all audio for both tracks comes out of the left channel.
If I double-click an audio event in the timeline to put it in the source viewer and play it, it comes out of both speakers centered.
I tried dragging a previously unused audio file into the timeline, creating a new audio track; it too played only out of the left channel.
This is beta 6.
Anyone else see this?