Dates?

I'm in the process of migrating a university site to Drupal 6. Our main site is currently HTML but we have a Drupal 5 installation used for publishing/archiving press releases and news. I attempted to import "story" nodes I exported from the Drupal 5 database. Everything looks perfect in the preview, but upon clicking "import" I received the following error:

An error occurred. /ocu/?q=admin/content/node_import/2/continue
Fatal error: Call to undefined function date_convert_from_custom() in /home4/ohiochri/public_html/ocu/sites/all/modules/node_import/node_import.inc on line 991

I'm attaching the node import debug report. I do have CCK enabled in the new install, but was not importing to or from CCK fields. I used node_import previously in another site and appreciate this module very much. Please let me know if I can offer any further information.

Thanks in advance.
Joy