Odd Merge problem...?

[Kenneth]

Howdy,

I run Word 2002 SP3 with XP.

I have a template that I use for printing certain labels. It
is a mailmerge document and its data source is a TXT file
saved to disc by my database.

Moments ago, I tried to run the macro that prints the label
I need, but I got an error:

LabelsMultOki.dot is a mailmerge document. Word cannot find
its data source Z:\MailMerge\let.txt.

The dialog gives me the option to search for the data file
manually. (At that point, I thought that the manual search
would fail, that is, I assumed there to be a problem causing
my database to fail in writing the data file.)

To my surprise, I browsed to the file, and it was just where
it should be: Z:\MailMerge\let.txt

Next, the Header Record Delimiters dialog displayed, as it
should (with the correct field and record delimiters
displayed, and also showing the correct data.)

So, I clicked OK, but...

The error appeared again:

LabelsMultOki.dot is a mailmerge document. Word cannot find
its data source Z:\MailMerge\let.txt.

So, what might be going on here?

Many thanks for any help,