I think this is the right issue queue for this problem. I was trying out this module in order to use AHAH Script Ensurer. None of my scripts were being "ensured" when I triggered the change event on Drupal core autocomplete elements.

I debugged the problem and found the origin with ahah_page_storage_init. The autocomplete GETs aren't arriving with the original page's ID, so a new one is being generated. However, the autocomplete function is returning that new page ID and it's being reset by the browser. When the AHAH behaviors are triggered, the page ID is different and I end up receiving jQuery.js and drupal.js again, which breaks the form big time... my Drupal.settings array is reset, my jQuery cache is reset, etc.