It seems to me that you could patch XML::Generator::DBI.

line 122 is:

A quick fix (untested!), that would work just for you would be to replace this by:

if( defined($row[$i]))
  { $proxy->send_tag($names->[$i], $row[$i], 3); }
else
  { $proxy->send_tag($names->[$i], '', 3); }
[download]

An even better fix would be to add an option in the new that would control whether SAX events are emitted or not for a NULL column.

Then send the patch to matts and make his day ;--)

Update: fixed the code (added brackets around the test). Thanks to gmax who tested it.