Problem with Net::Google::Calendar

This perl module looks like exactly what I want to do but I am having
trouble getting it to work. I am getting the following error when
trying to create an entry:

Can't call method "getElementsByTagNameNS" on an undefined value at
/usr/lib/perl5/site_perl/5.8.3/XML/Atom/Util.pm line 56.

I have narrowed it down to setting the when data. As an example:
$entry->when(DateTime->now, DateTime->now() + DateTime::Duration->new(
hours => 6 ) );

I have even tried to run the google-calendar code from the bin folder
on what I am assuming is Simon's subversion server. But it is late and
I might be missing something obvious.

Thanks,

--
Bill