One caveat that’s worth mentioning is replicating the XML data type in

SQL Server using Merge Replication.  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.

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.

After setting stream_blob_columns to false, articles containing XML columns should converge correctly in subsequent synchronizations.