I can reproduce this. dk-disks is fine, it recognizes the medium. gvfs also sees it:
$ gvfs-mount -o Monitoring events. Press Ctrl+C to quit. Drive changed: 'Optiarc DVD+-RW AD-5560A' Drive disconnected: 'Optiarc DVD+-RW AD-5560A'
However, there is no actual gvfs cdda:// volume for the audio CD. Banshee sees it just fine, but Rhythmbox and nautilus don't. So I suspect this is a problem in gvfs' cdda backend.
I can reproduce this. dk-disks is fine, it recognizes the medium. gvfs also sees it:
$ gvfs-mount -o
Monitoring events. Press Ctrl+C to quit.
Drive changed: 'Optiarc DVD+-RW AD-5560A'
Drive disconnected: 'Optiarc DVD+-RW AD-5560A'
However, there is no actual gvfs cdda:// volume for the audio CD. Banshee sees it just fine, but Rhythmbox and nautilus don't. So I suspect this is a problem in gvfs' cdda backend.