Background subtracted lightcurves for all four observations. Bottom panels: XMM-Newton and RXTE lightcurves, binned to a resolution of 96 s. Top panels: INTEGRAL-ISGRI lightcurves, binned to a resolution of 40 s. The black continuous line shows science window averaged count rates, i.e., averages over the ~30 min long individual INTEGRAL pointings. Data used in the analysis, i.e., data with roughly the same count rate level as that measured during the XMM-Newton observations, are shown in orange. Gray data points are from time intervals not used. The same flux variation is evident in all four instruments. Note that Obs4 is the shortest observation. See Table 1.