Sometimes, when replicating a table that contains a column of type XML via a Merge Publication, the XML column data in updated rows sent from Publisher to Subscriber, and vice-versa, arrive at the destination as empty, leading to non-convergence.
If you're experiencing this behavior, verify you have the latest Service Pack applied. If the problem continues to persist, execute sp_helpmergearticle on the Publisher to retrieve information about the article in question and examine the value of the article property stream_blob_columns.
DECLARE @publication AS sysname;
SET @publication = N'DBName';
@publication = @publication;
If the value of stream_blob_columns is set to true then this is the culprit. When stream_blob_columns is set to true, SQL Server uses data stream optimization when replicating LOBs. Somewhere in this optimization process things go south leading to non-convergence. To workaround this, execute sp_changemergearticle, set stream_blob_columns to false, and synchronize your subscriptions.
@article = 'TABLE_NAME',
@property = 'stream_blob_column',
@value = 'false'