If the two database instances are located in such away that you can link the offending table from one, into the other, then do that. Then build a query using the Unmatched Query wizard to determine what record is unmatched between the tables.
For example, assume in DB 1, you have the table DEMO and from the sycronization source you link in the same table which we will alias as DEMO1. Using the unmatched query wizard, you produce an SQL statement as follows:
SELECT [demo2].[Key], [demo2].[field1] FROM demo2 LEFT JOIN demo ON [demo2].[Key] = [demo].[Key]
WHERE ([demo].[Key] Is Null); petersdaniel@hotmail.com
"If A equals success, then the formula is: A=X+Y+Z. X is work. Y is play. Z is keep your mouth shut." --Albert Einstein