"Duplicate entry" error when addig a second field to a form

In both webform 5.x-1.9 and 5.x-1.x-dev when i attempt to create a form with more than one field, when I click "Submit" to save the form I get the following error message:

user warning: Duplicate entry '253-65535' for key 1 query: INSERT INTO webform_component (nid, cid, pid, form_key, name, type, value, extra, mandatory, weight) VALUES (253, 1205413820, 0, 'markup_1', 'Markup 1', 'markup', 'mark down', 'a:1:{s:6:\"format\";s:1:\"4\";}', 0, 0) in /home/content/a/n/s/answerjam/html/test/includes/database.mysql.inc on line 172.

The simplest case is 2 markup fields right under the form root (no fieldset).

Drupal 5.3, PHP 4.3.11, Apache, mySQL 5.0.45