S4 data dump or?

I am trying to dump some data in a file that I will add to a package.  The 
data has an attribute which is a S4 object, and this seems to cause problems. 
What is the preferred way to write a file with a dataset that has some S4 
parts, so that it can be included in a package?

Using save() seems almost always preferable to dump(): usually a 
smaller result, avoids representation error changes for numeric types 
and encoding issues for some character vectors, works for almost all 
objects.

I am guessing that the note on ?dump about objects of type S4 is the 
issue here.

Paul Gilbert

Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595