Autocomplete not showing up even though no exception has occured

While working with the Ajax tookit autocomplete extender, I have encountered a very strange problem. On one of the pages where autocomplete were setup, the autocomplete had a huge delay. There were no exceptions, the data was retrieved fine, when in debug mode, the autocomplete would show, but when running on the server, the autocomplete would show up after typing into the autocomplete around 10 times.

Using the YSlow plugin for Firefox, I was able to see the Ajax execution and the data retrieval, and there was no issues there, but the autocomplete were still not showing up.

After cutting out the code of the page bit by bit and testing the page, I was able to discover the whole problem was caused by the javascript focus function. At the bottom of the page, there was a focus function call on the textbox where the autocomplete extender is related to, and for some reason, this is causing a conflict with the javascript from the autocomplete extender, and the div which displays the autocomplete is not displayed.