DLL and Word XP merging

I have written a DLL to integrate an Access database with Word 2000 or XP. It displays a list of fields from queries in the database so the user can select which fields to merge. However, with Word 2002, every time you change anything, such as moving between one Word doc and another , it remerges all the data. If there are 2000 records, it takes forever. This happens probably 10-20 times setting up the document and then twice when actually printing a merge document which has been passed one record ID from the database.
It dosn't happen in Word 2000 - is there an option somewhere in 2002 where you can turn this off -its almost unworkable in an application environment

Hope someone can help - have scoured the MSDN and Microsoft but to no avail

thanks in advance
:)