In general, I have found this:  When using macros in Microsoft Access to
perform a mailmerge in Microsoft Word, it is not a good idea to connect the
main (unmerged) Word document to the Access database as the data source.
Instead, it's better to use the macros in Access to export the Access data
to an RTF (rich-text format) file and then get the macros to perform the
merge between the main (unmerged) Word document and the RTF file.  This
technique seems to avoid the problem of a second copy of Access opening when
the merge is performed and then not being easily to close that second copy
of Access.

I'm not sure if this will help you.  But your problem sounds perhaps
similar.

Geoff