Update sent in last night from ESA’s Mission Director Thomas Beck, at ATV-CC:

Today’s reboost of the ISS was successful. At 19:35 GMT (21:35 CEST), ATV Albert Einstein used its two main engines (OCS1 and OCS3) to
lift the ISS into a higher orbit. After a burn of 815 secs, the velocity of
the orbital complex was increased by 1.95 m/sec. The amount of
propellant burned for this manoeuvre was 271.6 kg.

The next reboost is planned for 23 October 2013, the final planned boost before ATV-4 departure from the ISS.