Banshee mp3 player problem

When I plug my Sony Walkman NWZ-A815 mp3 player in, banshee gives this error:

MTP support ignoring device
Banshee’s MTP audio player support can only handle one device at a time.

and I do not have any other MTP devices attached (as far as I know!). If I close banshee and re-attach the device, it mounts on the desktop as a mass storage device.

Does anyone have any ideas how to get banshee to import my device?