  We present new XMM-Newton observations of the intriguing warm absorber in I
Zwicky 1. This luminous and nearby narrow-line Seyfert 1 galaxy shows ionized
absorption by two components of outflowing gas; a low and a high-ionization
phase with log $\xi$~0 and log $\xi$~2 respectively. Detailed modelling of
these data reveal a complex and variable multi-phase warm absorber. However, we
find the changes in the ionization state of the gas not to be straightforwardly
correlated with the variability of the intrinsic continuum source, in apparent
contrast with photoionization equilibrium. The observed variability hints
instead at a close connection between the two gas components, possibly both
directly connected to the accretion disc activity. We thus suggest a
phenomenological model capable of explaining these observations, consisting of
a clumpy outflow where the high and the low-ionization components are closely
linked. Changes in ionization over the years are mainly driven by the different
densities of the clumps crossing the observer's line-of-sight, in which the
`skin' layer facing the source accounts for the more ionized component.
