I just installed Banshee from CVS and tried to burn an Audio Cd for my son. I was however presented with this error.

** (Banshee:5221): CRITICAL **:
nautilus_burn_recorder_write_tracks: assertion 
`tracks != NULL' failed
 

After a bit of searching it seemed like there was a patch available for libnautilus-burn4. But I didn't know where the update to it was. In the meantime I installed Bonfire and tried to burn the cd with that (it uses a different backend than libnautilus-burn4.) It fortunately gave me an error saying that I didn't have MP3 support installed. Indeed I didn't. Once I went into Synaptic and installed the required gstreamer packages and I went back to Banshee. Everything seems to be working fine now.