James, thanks for this. It seems to be a problem on the Mac, and perhaps an underpowered one at that: Air 2010. On my Windows machine it's not a problem.
On search, I seem to recall it was possible to filter out instant searches of, say Singapore from a search of Sing by typing <sing> and then hitting <space>. This would filter out any words of which <sing> were just the first four letters. That no longer seems to work.