With the web app, the search function seems to only search through items that are on the page you are currently looking at. This is essentially useless, since if I knew where that thing that I wanted was, I wouldn't need to search for it! I realize the there is the advanced search, but it doesn't seem that even this will accomplish the simple task of searching for the word "foo" and returning all of the items that contain that word.
In my opinion, search should also return items that are marked as completed.
Duh... I figured this out. Near the magnifying glass icon, click the down arrow and you can select 'current' or 'global'. Global is exactly what I wanted. I think it should be the default.