Ed,
Thanks for your help on this. It was surprisingly easy to get it working. I can now make searches with an empty word and searchindex table (although the results leave a little to be desired at the moment).
I'm having a bit of trouble with the 'IN BOOLEAN' modifier. Even with + in front of every word, it still seems to return stuff that doesn't contain all words. I suppose I can't expect too much at the moment... 4.01 is only alpha, after all.
Thanks again for your help Ed.