When an element has "background-attachment: fixed" set, the background-image will be displaced while a transition of -webkit-filter is active.
It should be visible over here, when you hover over the image:
I'm using Chrome 31 on a Windows 7 PC.
I don't see displacement on this test case in Safari. There is some jagginess due to different antialiasing options while transitioning though, so it doesn't look particularly nice.
Please note that Chromium has forked away from WebKit, so they have a separate bug tracker now.