  IRAS13349+2438 was the first quasar suggested to host a warm absorber with
internal dust. We obtained new HRI data for this object and derive constraints
on the X-ray emitting region of IRAS13349+2438 by investigating its X-ray
extent and lightcurve. Rapid X-ray variability is detected with a factor of two
change in count rate within one day and 20% variability within about three
hours, which practically rules out any significant contribution of scattered
X-rays. We present for the first time a detailed, self-consistent modeling of
the ROSAT PSPC and ASCA spectrum of IRAS13349+2438 in terms of a warm absorber
including dust. It turns out that both a dust-free and a dusty single-component
warm absorber fail to explain the ROSAT, ASCA, and optical data simultaneously.
We discuss possible explanations such as a variable and/or complex warm
absorber, a variable soft X-ray continuum and instrumental effects.
