"Ignore pages:" does not work

On the configuration page:
Make secure only the listed pages is selected.
Pages:
node/add*
node/*/edit
user*
admin*
as well as my Ubercart /cart and /cart/checkout pages

Ignore pages:
*/autocomplete/*
*/ajax/*
The pages listed here will be ignored and be either returned in http or https. Enter one page per line as Drupal paths. The '*' character is a wildcard. Example paths are 'blog' for the blog page and 'blog/*' for every personal blog. '' is the front page.

With Secure Pages configured this way ajax and autocomplete callbacks should work whether they are returned as "http://" or "https://" and whether or not they are called from secure pages like those listed above. At least that's my understanding of this setting.

However, I am getting the following errors with ajax and autocomplete:

On the page https://mydomain.com/node/add/user-notes I get the following error when trying to edit a user reference field:
"An HTTP error 0 occurred.
"http://mydomain.com/userreference/autocomplete/field_user"

On the page https://mydomain.com/admin/build/views/add I get the following when trying to create a new view:
"An HTTP error 0 occurred.
"http://mydomain.com/admin/views/ajax/autocomplete/tag"

What's happening here seems to be that function calls are being made from https pages and the functions are returning http pages. It seems that Secure Pages should ignore them and allow the http returns because they are ajax and/or autocomplete pages. However, that's not happening. This is occurring both on a live site and a test site.

I've seen other related posts concerning not switching between http and https but none that directly addressed this issue.