I'd like to know what the common bugs are out there. So far, I think one of them is Mail not working sometimes with iCloud IMAP accounts. Here's a list of what I've seen: Dock randomly switches to other screen. (http://forums.macrumors.com/showthread.php?p=18209934#post18209934) This happened for me when I used VNC. Slow performance after the installation for about an hour. A lot of inactive RAM even after that (not sure if a problem or not). Java got uninstalled. Mail sometimes can't connect to iCloud IMAP accounts. Pages '08 can't save without crashing after (though it still saves). A few libraries and video drivers corrupted on one Mac. Time Machine menu item doesn't spin when it's backing up. (added Oct 25) The kernel task shows as using a LOT of RAM under "real mem" but a much smaller, more normal amount under "memory" in Activity Monitor. I don't know what the difference is or if this is a bug. Originally Posted by Sylon: Quick Look is choppy as hell when viewing videos (I've heard of this.) Originally Posted by bobright: SMB is still jacked up full of errors....smh (I had it fail twice.) Anything else?