Losing Mail Merge DataSource

[Conor]

I have a problem with losing the data source of my mail merge
document. I created a mail merge document called MergeTest and set its
main document type to Letters. I then ran the following code:


Set wApp = CreateObject("Word.Application")
Set wDoc1 = wApp.Documents.Open("MergeTest.doc")
wDoc1.MailMerge.OpenDataSource "301.tmp"
''' *1*
wDoc1.Close

Set wDoc1 = wApp.Documents.Open("MergeTest.doc")
''' *2*
wDoc1.Close


At stage *1* its state is wdMainAndDataSource, but when reopened it
seems to reset to wdNormalDocument (*2*).

Is there a parameter or setting I'm not aware of?

Conor.