Just downloaded through software update the update to Apple's Jaguar OS X operating system. First comment: why did I do it? These updates are usually no-brainers. But for some reason the improved performance in “mail” and “address book” is just not happening. On re-boot after install, Mail refused to open and continously quit. How? You guessed it. Unexpectedly. Explorer seems to run slower and overall I just feel a little sluggish. Anyone else experiencing this?