Will be fixed as http://www.ventismedia.com/mantis/view.php?id=13068 , there are unexpected UTF-8 BOM chars causing the duplications

I'm No expert but I cant help but notice in your screenshot Its showing ¥ as the separator, could this be related?

You can offer the database to support for analysis: http://www.mediamonkey.com/support/index.php?/Tickets/Submit

I'm afraid you'll need to start with a clean database to get rid of the problem.

I ran 'Maintain Library' with full optimization but the duplicated artists are still there

[img]http://i.imgur.com/pISMuNY.png[/img]

It sounds like a database corruption may be the problem. Running File > Maintain Library with complete optimization checked may resolve it.

I am using version 4.1.9.1764. Within the Media Tree column, there are 2 'Betty', 2 'Chelly', 2 'Diane' but only 1 'Anna'.

Which version of MediaMonkey and does the Artist have a single or also multiple entries in the Artist node in the Media Tree?

I looked for similar threads but found nothing similar to my query. Supposedly I have these 2 songs in a database. (Tagged using mp3tag).

Title: Air
Artist: Anna\\Betty\\Chelly\\Diane

Title: Break
Artist: Sphere\\Anna\\Betty\\Chelly\\Diane

Air is sung by 4 people. Break is sung by 4 people under the name 'Sphere'. Taking a look at the artist column within the Column Browser, Anna has two separate entries.

[img]http://i.imgur.com/4dtQ2QL.png[/img]

This problem becomes much more rampant when dealing with artist singing solo and within a group. The position of the artist's name seems to matter a great deal when sorting by artist. Is there anyway to merge the artist together?