Just thought I'd share this with everyone. Was getting frustrated with crashing Pages/Numbers/Keynote on launch after installing iWork with latest update, along with Snow Leopard 10.6.5 combo update and disk permissions check. To cut a long story short, the issue was due to a corrupt user font. I disabled 'user' fonts using the Font Book utility and that seems to have done the trick. Next thing to do would be to isolate the problematic font, but at least I can get on with some work now!