One thing we lost in the recent upgrade of the jquery in tracks was it selected the first matching entry of a context or project in the form fields. As such, you have to press the down arrow key or mouse click to select one.

So I looked about and found this jquery extension:
https://github.com/scottgonzalez/jquery-ui-extensions/blob/master/autocomplete/jquery.ui.autocomplete.selectFirst.js
described here:
http://forum.jquery.com/topic/autocomplete-automatically-select-first-item-in-dropdown-or-add-item-into-drop-down-menu

So I dropped it in to my tracks and got it to work without too much trouble. I added a new js file to public/javascript and added some code to the application.js function enable_rich_interaction. I also added the new js file to the javascript_include_tag in standard.html.erb.
Maybe there is a better way, but this seems to work. Let me know if I am doing something poorly. I am not sure if tracks wants an extension that is not in the official release.

I created a branch with the commit off the current upstream master and pushed it to my github. See here: https://github.com/maddentim/tracks/commit/fdd1c8d54d167d18b88b46eb1b4ae4b134175389