Hey Rc,
When you import the audio file or drag it to an audio track, you should be able to click and hold on the little circle or symbol below the channel strips Level Meter and then select Mono, Stereo, Left channel, Right channel or surround.
[img]http://img689.imageshack.us/img689/220/picture3du.png[/img]
Hope that helps :)
Rounik