i tested it out for teh waiting bit,
if you go to the same level as you mule can get ex. the first act1 village.
with 1,5 minites it's safe to exit the game and go in with your mule character.
i'm gessing about 1 minute would do too, but i take a little bit on the safe side <img src="/ubbthreads/images/graemlins/biggrin.gif" alt="" />


Carpe diem, quam minimum credula postero