Program locked up
I searched for a single letter because I wasn't sure how someone's name was spelled, and now my program's locked up!
Don't panic, the directory is just returning every single entry that matches your search. Since there are likely thousands of matches for a single letter query, it will take a long time to finish. If you are in Eudora, hit the 'stop' button to cancel the search. If you are in another program, wait for the search to finish or force quit the program (In Windows you can do this by hitting control-alt-delete).