Drupal user profile view and edit screens contain different information

We're using CiviCRM and collecting user's names, addresses, etc.. using the CiviCRM profile management stuff.

We've recently had about 6 complaints from users who are noticing that the 'view user profile' and 'edit user profile' pages don't match up as far as the CiviCRM data is concerned.

A user goes to the '/user/NNN' page and views his "constituent information" and sees one set of data.

He selects "edit" and then the "constituent information" tab and sees a different set of data. Data that corresponds presumeably to some other user entirely.

This problem exhibits both under 1.4 and 1.5.

We do have other things going on on the site, naturally, but nothing that should be getting in the way of CiviCRM and it's management of "constituent information".

These screenshots show the problem clearly. They do contain actual user personal information, and I'd like them deleted on close of this ticket