still expected consistent with the 401 Hz pulsations observed.

@wij04 reported a modulation at a repetition frequency of $\sim 1$Hz that completely dominates the lightcurve of J1808 in the 2000 and 2002 outbursts. This $\sim1$ Hz modulation appears as sudden intensification of the X-ray flux that are obvious in the power spectra and sometimes are directly detected in the lightcurve. A re-analysis of these data, along with a complete investigation of this phenomenon for the other three outbursts (1998, 2005 and 2008), is presented in this paper.

The mechanism of the re-flares and the 1 Hz modulation is still unclear, but it might be related to the onset of instabilities expected for sources near the propeller stage (@ust06). It has been suggested that the fast decay and the re-flares are related to cooling and re-heating fronts propagating through the disk (@dub01). The heating fronts change the accretion disk structure from a neutral to an ionized state, increasing the viscosity and the mass transfer rate through the inner accretion disk. If the inner disk structure is influenced by this process, the disk-magnetospheric boundary and/or the accretion process can be modified as well, possibly producing hydrodynamic instabilities in the accretion flow [@goo97; 