jframe jquery pluging problem with drupal autocomplete

I'm facing a problem related to the use of the jframe jquery plugin (http://plugins.jquery.com/project/jframe) along with the autocomplete javascript in Drupal.

I'm using jframe to load some frames within a drupal page and in one case one of the frames loads a drupal form which contains an autocomplete field. That form element doesn't work properly. However, the same form loaded within another frame from the beginning works fine.

I've no idea where to begin to look for the problem. Any help will be very much appreciated.