Unwanted playlist with (invisible) null -- null tracks

Hi,

After I installed 'MiniPlaylist' add-on, I found a very annoying complex problem. At the first time I believed it's a simple add-on bug. But later I realized, it's more than a simply bug.

So:
- When I chose MiniPlayList->Change Playlist->Library an error message came up.
Screenshot: http://img10.imageshack.us/img10/9269...
If I pressed 'Continue' nothing (visible) happened (no sound).
- Then if I chose MiniPlayList->Most Played, I saw sometimes 9, sometimes 10 strange tracks (null -- null).
Screenshot: http://img11.imageshack.us/img11/2543...
- If 'Recommended Playlists' is installed a new playlist appeared with those (invisible) null tracks.
Screenshot: http://img9.imageshack.us/img9/2667/s...
If I deleted this unwanted playlist, it's came back every time when I started or restarted Songbird.
If I deleted 'MiniPlaylist' add-on, the playlist came back again.
But if I deleted 'Recommended Playlists' as well, the playlist is disappeared (because 'Recommended Playlists' add-on made it to see but not caused it).
- If 'Now Playing List' is installed and I chose the unwanted playlist to play, the null tracks are appeared but nothing happened (no sound).
Screenshot: http://img10.imageshack.us/img10/4959...
I tested in an empty, totally new profile.

After I deleted that profile and created a new one without any add-on. Then I installed only 'Recommended Playlists', the strange unwanted playlist (with null tracks) came back again! Even if 'MiniPlaylist' was not installed.

So I decided to uninstall Songbird too, and I deleted all Songbird stuffs (profiles etc.) what I found:
- C:\Documents and Settings\Hiromacu\Local Settings\Application Data\Songbird2
- C:\Documents and Settings\Hiromacu\Application Data\Songbird2

Then I reinstalled Songbird without any add-on and I installed only 'Recommended Playlists'.
But the strange unwanted playlist (with null tracks) came back again!!! I had no problem with 'Recommended Playlists' before I installed 'MiniPlaylist' and I'm not sure this is an add-on problem. Maybe a Songbird core problem.

So something happened with the playlists and I can't do nothing! I don't want to reinstall my whole OP system.

Songbird 1.1.1, Build 1018 (20090309144748)
Windows XP MCE Version 2002 (SP3)