We now use the following rules for Sleepwalkers, found as "errata" in the MET Awakening book on page 434
Sleepwalker (3 or 4 dot merit)
Prerequisites: Mortal
Your character is not completely asleep; the Quiescence does not affect
him fully, and he is not susceptible to Disbelief. He can witness improbable
or vulgar magic without increasing the chances of a Paradox. At four dots, the
Sleepwalker also has a mage’s Unseen Senses.
Note: A Sleepwalker is also immune to Lunacy.
Sleepwalker (3 or 4 dot merit)
Prerequisites: Mortal
Your character is not completely asleep; the Quiescence does not affect
him fully, and he is not susceptible to Disbelief. He can witness improbable
or vulgar magic without increasing the chances of a Paradox. At four dots, the
Sleepwalker also has a mage’s Unseen Senses.
Note: A Sleepwalker is also immune to Lunacy.