Unable to get the search module to perform index

Hi,

I am working with drupal 5.2 with the core search module. I have 3 sites with a single code base.

The first site indexing works fine by running cron.php.

For the other two sites when i run cron.php, the page immediately returns a blank page, and does not index any content.

From what i can tell i have performed the steps as described in http://drupal.org/node/44963

It does not appear that cron ever starts the index process.

Any insight would be helpful

Thanks,

Matt