Modifying Label Template Breaking Link to Access Table

Hello All,
Noobie with AutoCAD 2007 and AutoCAD in general, so here is a last
ditch effort to correct a problem I have with a legacy file that I
inhereted several months ago.
The file contains objects that are linked to an Access table through
an ODBC connection. We have a label template that displays data
associated to objects on the file.
Whenever I modify the Label Template to include new data fields and
then reload labels, I lose all connection to the db and the label
displays the field names.
This happens with all the files I have. I know it is probably
something simple that I am missing...
Any help would be great.
JB