Try copying the data to a new workbook and see if that helps.
Naming the data range something like Database also seems to help

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HTH
Nick Hodge
Microsoft MVP - Excel
Southampton, England
www.nickhodge.co.uk
nick_hodgeTAKETHISOUT@zen.co.uk.ANDTHIS
>I am trying to mail merge from excel for labels, I have used this file many
> times, but all the sudden it is saying can not re-establish DDE connection