I see this a great deal when having multiple moz. windows open... 1) Open browser to a page 2) Open Preferences 3) dismiss (x or cancel) preferences 4) notice about a 1-3 second delay before the browser refreshes. The refresh is fast, but it seems to wait a moment after the top window is dismissed.
Other windows (compose, address book, browser) have the same affect when dismissed. this seems to be a new effect, as I'm just noticing it with RCs.
