This isn't a problem with Chrome .. you're just misunderstanding what the privacy mode does. Incognito is not meant to be a clean slate.
When you're in stealth mode, nothing that you do is recorded. However, everything that you did in 'normal' mode remains accessible. It doesn't reset any settings.
If you're in stealth mode and you type 'www.maxi' into the URL bar, it will autocomplete http://www.maximumpc.com
(for instance) if you've been to maximumpc.com using the browser. Stealth mode does NOT wipe or ignore previous history .. it only prevents current
browsing from being recorded.
If you want to run Chrome without autocomplete or previous history interfering with your browsing, the easiest thing to do is to run the browser using a different user account (as suggested earlier).