Comment 2 for bug 435336

This preexec does not get shipped with Ubuntu, does it?

You might want to escape it using $'', like:
   print -Pn $'\e]0;$1\a'

See also the "print"'s in the title() function of my oh-my-zsh fork at:
https://github.com/blueyed/oh-my-zsh/blob/8d5105135772ae0c3c81850cea422cc322ed6f7d/lib/termsupport.zsh#L27