[Banshee-List] Track dictionary in TrackListDatabaseModel

[LCID Fire <lcid-fire gmx net>]

I was looking into TrackListDatabaseModel and wondered why the tracks
are managed in a Dictionary?
Currently it's defined like:
private Dictionary<int, LibraryTrackInfo> tracks = new Dictionary<int,
LibraryTrackInfo>();

the key is used to determine whether a certain index is already read:
if(tracks.ContainsKey(index)) {

I'd say it would make more sense to have this as a list:
private List<LibraryTrackInfo> tracks = new List<LibraryTrackInfo>();

determining would then work like:
if(index < tracks.Count && tracks[index] != null) {

and of course instead of adding the read TrackInfos have to be
inserted/replaced.

That should do the trick, make the code easier to understand and more
performant.

BTW: Are you sure the locking works fine this way?