[Koha] add item returns production mode - trapped fatal error

[Marty]

Running on debian etch, nozebra (for now), I can import books from Library of Congress Z3950 server, but when I am in items and click on add item, I get this production mode - trapped fatal error message.
The added items show up in the mysql biblio table (but not in items, obviously)

The koha logs don't show errors, the apache log does:
[Sun Apr 26 15:45:26 2009] additem.pl: Can't call method "append_fields" on an undefined value at /usr/local/share/perl/5.8.8/MARC/File/SAX.pm line 95. at /usr/local/lib/perl/5.8.8/XML/LibXML/SAX.pm line 73
[Sun Apr 26 15:45:26 2009] additem.pl:  at /usr/local/share/perl/5.8.8/MARC/File/XML.pm line 445
[Sun Apr 26 15:52:46 2009] additem.pl: Can't call method "append_fields" on an undefined value at /usr/local/share/perl/5.8.8/MARC/File/SAX.pm line 95. at /usr/local/lib/perl/5.8.8/XML/LibXML/SAX.pm line 73
[Sun Apr 26 15:52:46 2009] additem.pl:  at /usr/local/share/perl/5.8.8/MARC/File/XML.pm line 445
[Sun Apr 26 15:54:35 2009] [error] [client 192.168.0.101] File does not exist: /var/www/HNAP1
[Sun Apr 26 15:54:38 2009] [error] [client 192.168.0.101] File does not exist: /var/www/TEADevInfo

Any ideas or suggestions welcome, thanks, Marty