jQuery 1.3.2 + jQuery UI 1.7.2 + Autocomplete 1.8.?

jQuery 1.3.2 + jQuery UI 1.7.2 + Autocomplete 1.8.?

Hi All,
I have to integrate the autocomplete widget into an application which have jQuery 1.3.2 and jQuery UI 1.7.2. I can't upgrade the jQuery version.
I added the autocomplete 1.8.1 + position widget. I don't get any errors, but it doesn't works.
Any ideas?
Thank you,
Davide