Mail merge is merging information from multiple records.

[DaveAtFpmsi]

I created a letter with multiple merge fields. On some of the letters Word is
filling in what should be blank fields with information from other records.
It is random and usually is pulling information from the last record to have
data in the field.

 

[Peter Jamieson]

Which version of Word, and what is the data source? One such problem is
described in

http://support.microsoft.com/default.aspx?scid=kb;en-us;204542

Peter Jamieson