CD import not using Album Artist for directory names as it should

I've imported a CD using Banshee, where there are two tracks that have an artist which is not the album artist. The Banshee option for directory naming has been set to Album Artist/Album (Preferences / Source Specific / Music option File Organization). However, what gets imported ignores this, and creates three albums under each distinct track artist.

The specific album can be found in Musicbrainz, which is of course where Banshee fetched this information. See Stevie Nicks' Bella Donna http://musicbrainz.org/release/e48447b2-7f45-3d0d-aa04-161de37ff788 . The Album Artist is Stevie Nicks, so all tracks should appear under "Music/Stevie Nicks/Bella Donna". However, after import, only 8 of the 10 tracks are in that folder. Track 3 is under "Music/Stevie Nicks & Tom Petty/Bella Donna" and track 8 is in folder "Music/Stevie Nicks & Don Henley/Bella Donna". I in effect have 3 albums, none of which have all 10 tracks of the CD that I imported.

ProblemType: Bug
DistroRelease: Ubuntu 11.10
Package: banshee 2.2.0-1ubuntu2
ProcVersionSignature: Ubuntu 3.0.0-12.20-generic 3.0.4
Uname: Linux 3.0.0-12-generic x86_64
NonfreeKernelModules: fglrx
ApportVersion: 1.23-0ubuntu3
Architecture: amd64
Date: Fri Oct 21 21:27:17 2011
InstallationMedia: Ubuntu 9.10 "Karmic Koala" - Release amd64 (20091027)
ProcEnviron:
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: banshee
UpgradeStatus: Upgraded to oneiric on 2011-10-15 (6 days ago)