Automatic alias settings per node not saved

I am running Drupal 6.4

When I create content and set the automatic alias to be unchecked and supply it an alias everything works fine. When I open the node again and edit it, the automatic alias checkbox is checked again but the supplied alias is still there. If you dont uncheck that box before you submit the node, it will destroy the supplied alias and create a new one as you instructed in the autoalias administration page.

I think the Automatic alias checkbox should remain unchecked if it has a supplied alias (one that doesnt conform to the format you specified if done automatically). This would allow you to maintain your alias across edits of a node without having to uncheck the Automatic alias button each time you submit a change