[linux-audio-user] Xitel Pro Hifi-link playing mono, not stereo (Fedora Core 6)

Hi, I have a Xitel Pro HiFi-link usb soundcard which works fine in Linux, except that it appears to be sending the same signal to both left and right channels. If I start up e.g. Audacity, import a track and pan it all the way to the left or right it still plays in both channels. The same thing happens in Ardour so I don't think it's a software specific thing. I've had this problem in FC5 and FC6. The sound was fine before that (FC4 I think). This is my first time playing around with Linux audio so if anyone could suggest how to start fixing this I'd be grateful. I can post any log/config files. Thanks, Martin