We present a series of monitoring observations of the ultrasoft broad-line Seyfert galaxy RE J2248-511 with XMM-Newton .
Previous X-ray observations showed a transition from a very soft state to a harder state five years later .
We find that the ultrasoft X-ray excess has re-emerged , yet there is no change in the hard power-law .
Reflection models with a reflection fraction of \geq 15 , and Comptonisation models with two components of different temperatures and optical depths ( kT _ { 1 } = 83 keV , T _ { 1 } = 30 eV , \tau _ { 1 } = 0.8 ; kT _ { 2 } = 3.5 keV , T _ { 2 } = 60 eV , \tau _ { 2 } = 2.8 ) can be fit to the spectrum , but can not be constrained .
The best representation of the spectrum is a model consisting of two blackbodies ( kT _ { 1 } = 0.09 \pm 0.01 keV , kT _ { 2 } = 0.21 \pm 0.03 keV ) plus a power-law ( \Gamma = 1.8 \pm 0.08 ) .
We also present simultaneous optical and infrared data showing that the optical spectral slope also changes dramatically on timescales of years .
If the optical to X-ray flux comes primarily from a Comptonised accretion disk we obtain estimates for the black hole mass \sim 10 ^ { 8 } \mbox { $ \mbox { M } _ { \odot } $ } , accretion rate \sim 0.8 \dot { M } _ { Edd } and inclination \cos ( i ) \geq 0.8 of the disk .