Merge numbered lists in Word

Here is a challenge I stumbled upon in Word 2010, and was wondering if anyone has any better answer to resolve this...

I am doing a mail merge document which has a numbered list 1-8. When I merge the document the first time the list in each document is 1-8. However, if I go back into the document after I have saved it and closed it the numbers change in each document. The second document will be 9-16, the third document will be 17-24 and on and on and on. Not even the section breaks that the mail merge adds to the end of each document prevents the bullet list from changing after save and re-open.

I obviously can change the bullet numbers to plain number to solve the issue...I even found a macro that can do this for me [as below]

Sub ConvertToPlainNumbers[]
ActiveDocument.ConvertNumbersToText
End Sub

However...
Is this a bug in the program?
Is there a better solution than converting the bullet numbers to plain text?
Any ideas?

TX

Regards,
Rudi

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