The Find box now has forward/backward radio buttons. Find Next
searches forward, and Find Previous searches backward, regardless
of the direction of the initial search.
The standard key sequence for "find previous" is Shift+F3. The WPF
ListView has some weird logic that does something like: if you hit
a key, and the selection changes, and the shift key was held down,
then you must have meant to select a range. So Shift+F3 often (but
not always) selects a range. I think this might be fixable if I can
figure out how ListView keeps track of the current keyboard
navigation position (which is not the same as the selection). For
now I'm working around the problem by using Ctrl+F3 to search.
Yay WPF.