PDF attachements in Endnote X1 when Importing library

When I import a whole Endnote library into another Endnote library via the File Import option the file attachments don’t seem to come across with the citations.  Is this normal?  If I have both Endnote libraries open and cut and paste the citations across this seems to copy the file attachment.  But I want to merge several large endnote libraries and I want the file attachments to come across with the citations.  How do I make sure this happens?