  We analyze four XMM-Newton galaxy clusters in order to test whether their
soft X-ray excess emission in the 0.2-0.5 keV band as reported by Kaastra et
al. (2003) maintains after the application of the current knowledge of the
XMM-Newton background and calibration. We show that in the bright central 500
kpc regions the details of the background modeling are insignificant. Thus, the
cluster soft excess is not a background artifact, contrary to recent claims by
Bregman et al. (2006). We find evidence that the change in PN calibration
between years 2002 and 2005 results in significant decrease of the soft excess
signal. However, the MOS instruments measure significant amounts of soft
excess, or sub-Galactic NH. These differences are compatible with the current
level of uncertainty in the calibration of both instruments.
