Here's an oddity. On all my Macs, upon restarting they will try to launch the software listed in my login items, but from attached disks (specifically my clone drives). So I get a message, "This is the first time running this software downloaded from the Internet. Do you wish to proceed?". I tell it no and then manually launch whatever they are after the restart is finished.
It's always the same apps, although sometimes a new one will add itself to the list of those that do this. They are all apps I've downloaded from the Mac App Store. I've tried deleting them from the login items and re-adding them but it doesn't work.
I do keep my clone drives unmounted after the cloning is finished, but of course when the computer restarts the drives mount themselves.