One quick suggestion is to somehow give the user a way to halt the search updating. For example, the user starts typing and the results start coming into the results box. The user sees one he/she likes but by the time they have pressed the number to launch it, it has been moved! I understand that you can turn off automatic updating in the options, but perhaps you could have a key that, when pressed, would stop the box from updating. The search would continue however, and when the user released the key (or tapped it again possibly) the screen would resume updating with the current search results.
Sorry if that was confusing... I realize the demand for this could be pretty minimal. I only suggest it because I have done it quite a few times. Let me know if you have any questions as to what I mean. Also, if it adversly affects program complexity, consider it "not suggested!"