You can run the smart index wizard as many times as you like. It shouldn't however find new index keywords unless the settings you used in have changed. One of the options in the wizard is to allow you to choose which keywords it finds are actually added to the index. If you are using the wizard this is the best way to go. Personally though I have never found the wizard a good way to build the index. The algorithum it uses finds all sorts of unwanted stuff. I've always manually built the index via the topic properties dialog. I just find it so much easier, especially when you can use "keyword\subkeyword" to add two index levels.
Thanks for the reply. I'm rapidly coming to the same conclusion about the Smart Index Wizard. It looks like, if "Find New And Existing Index Keywords" is selected, the wizard will add keywords based on topic content AND existing index entries. This would explain why the wizard finds new words each time it's run.
My multiple runs of the wizard on my small project resulted in 6448 entries added the first time, 4191 the second, 154 the thrid and 69 entries added the fourth. Seems like it picks up nearly every word and phrase outside of the ignore list.
A lot of what the wizard puts out is clearly useless. The wizard is also not as useful as it could be since it filters on topic Status and not CBT. Howver, I've saved off the .hhk file as I do like to peruse it for words I've missed and suggested phrases. It's also good to give you a veiw of just how many places a word or phrase is being used - helps me to see how common it is and whehter I want to include it or not.