I'd be surprised if you were getting a /message/ as a result of the values
of the fields being too long. Word generally just truncates the data and
says nothing.

I don't know all the rules for dealing with names, but for text files in
Word 2003, Word
a. truncates names over 40 characters.
b. if you connect using ODBC or Word's internal text converter, word
displays the same names in dropdowns as the field names it recognises.
however, if you connect using OLEDB, it displays a name, truncated to 64
characters, in the drop-down filed insertion menu on the merge toolbar and
in the Mail Merge Recipients box. However, it may not display the actual
name - it may display the name preceded by the filename and a #.
c. If you have 2 long names over 40 characters and the first 40 characters
are the same, with the text converter, Word will "mangle" the names, e.g. if
the 40 characters end in xxx, the first name will probably end in xxx and
the second in xx1, but of course there could be a real name whose first 40
characters ends in xx1, so the algorithm needs to be a bit more complicated.
ISTR there used to be a knowledgebase article about this. However, with
OLEDB Word truncates both  names and it becomes impossible to insert the
data for the second name using a mergefield.

So I guess it's not a bad idea to stick to names less than 40 characters
long...

Peter Jamieson