(Top panel) APEX and VLT light curves plotted on the same scale. Theoretical predictions of model I for several wavelengths are overplotted in blue. (Middle panel) Magnified view of the VLT data. (Bottom panel) The synchrotron and SSC curves give the initial SED of the plasmoid in model I. They fit the simulaneous NIR and X-ray data (in red and blue respectively) of Flare A. The non-simultaneous sub-mm data of Flare A′ are also indicated in green for information. The references of the quiescence data in light gray are given in Trap et al. (2010).