I don't know if it is your cup of tea but we also have a brand new hostel here in Leuven. Extra nice is that the festival shuttles drop you off about 50 metres from the hostel! Go to the back of the station, use the pedestrians tunnel under the tracks. The shuttles leave from the parking lot there for the festival and the hostel is across the street. spam: you can find some information on Leuven on my pages ;-) Enjoy your stay and the festival!