1. S. Herminghaus, K. Jacobs, A. Fery, M. Ibn-Elhaj, S. Schlagowski, Max Planck Institute for Colloid and Interface Science, Rudower Chaussee 5, D-12489 Berlin-Adlershof, Germany. K. Mecke, Physics Faculty of the University of Wuppertal, D-42097 Wuppertal, Germany. J. Bischof, Faculty of Physics of the University of Konstanz, Post Office Box 5560, D-78434 Konstanz, Germany.