I encountered the same problem in DBD::ADO::Const:

  It seems that all available type libraries are checked
  (for whatever reason). In a networking environment, the
  performance may be unacceptable.

  http://search.cpan.org/~sgoeldner/DBD-ADO-2.95/lib/DBD/ADO/Const.pm
[download]

and implemented an alternative to Win32::OLE::Const.