Not smarter or wiser KrisG, just passing on the info I received when I had the same problem.

Tom, I have my slider set at extra small, but I still get some latency with amplitube, but it's useable. If I move the slider too far to the left I do get crackles on my playback, but I've only got 1gb of ram. If you have more Ram you might be ok with lower settings. It's all related to your computer setup (I think). But just play around with it because Amplitube is worth the effort; although the model packs I've recently got for Gearbox mean I use that most of the time now.
I like my new member status, 'beer buying not quite so new member' - that must be Scott...
