Well, I finally bit the bullet and purchased a new EOS-40D with the 17-85 IS USM kit lens today, and promptly started exploring this fantastic bit of kit.
My delight was short lived however when I noticed an strange speck on an image I'd taken using live view hooked up to my PC...
A bit of pixel peeping later revealed a dead pixel just below left of centre on all images
It's definitely dead rather than 'hot', as it shows up on all images regardless of ISO setting or shutter speed.
Suffice to say that I shall be returning to Jessops tomorrow for an exchange.
Follow link below for a couple of 100% crops to see what I mean: