citation numbering not chronological

I have difficulties with obtaining correct, chronological, citation numbering in my document.

For unknown reasons, the first citation is numbered  as the second (2), whereas the second citation is numbered as first (1). The rest of the document has correct numbering. I’ve tried deleting and reinserting all citations & unformatting and reformatting of citations without succes. 

When starting the document all over without citations, everything goes all right for a few citations, but in a while the numbering problems returns again. The second citation (incorrectly numbered as 1) is used frequently throughout the document.

I am using Microsoft Word 2002 and EndNote version X.

Any suggestions would be more than welcome! 

Do you have any text boxes in the document?  They get picked up first - you need to change them to “frames” I think to avoid this, or to make them “dummy” references.