This error has been reported to us only once but we have been able to replicate it and feel it is worth mentioning here. The problem lies in the installation of MS Access itself. It relates to an invalid reference to the Microsoft DAO library. This error manifested itself mainly in MS Access 97. Newer versions of MS Access using the Microsoft DAO 3.6 Object Library do not exhibit this behaviour.
A very similar error has also been reported whilst running under a non-English version of MS Access. This error has been corrected as of the SAP Data Downloader version 2.11.