Heh. I was just about to post this. This is still an issue, I guess, three months later.
The complaint doesn't really have anything to do with the effectiveness of the search itself, so deleting a character and re-typing doesn't help. The real problem is that the dynamic dropdown-list has the first item selected by default. (Compare to Google's auto-complete dropdown, which has nothing selected until you use the arrow keys or mouse to select it.) As a result, hitting ENTER (or clicking the search button, per the original post) after typing your search term takes you to the first item in the list, which is very often not what you want.
My workaround has been to hit ESC (to dismiss the dropdown) before hitting ENTER. This gets you to the proper "search-results" page.
I was pulling my hair out trying to search for "Air" until I figured that out. Kinda annoying.