Reply to the Comment by W.-J. Kim et al. C. Braggio, G. Bressi, G. Carugno, C. Del Noce, G. Galeazzi, A. Lombardi, A. Palmieri, G. Ruoso and D. Zanello EPL, 78 2 (2007) 21003 Published online: 02 April 2007 DOI: 10.1209/0295-5075/78/21003