We report on optical and X–ray observations of the accretion powered ms pulsar IGR J00291+5934 in quiescence .
Time resolved I –band photometry has been obtained with the 4.2 m William Herschel Telescope , while a 3 ks Chandra observation provided contemporaneous X–ray coverage .
We found an unabsorbed 0.5–10 keV X–ray flux of 1 \times 10 ^ { -13 } erg cm ^ { -2 } s ^ { -1 } which implies that the source was in quiescence at the time of the optical observations .
Nevertheless , the optical I –band light curve of IGR J00291+5934 shows evidence for strong flaring .
After removal of the strongest flares , we find evidence for an orbital modulation in the phase folded I –band light curve .
The overall modulation can be described by effects resulting from the presence of a superhump .
Comparing our lightcurve with that reported recently we find evidence for a change in the quiescent base level .
Similar changes have now been reported for 4 soft X–ray transients implying that they may be a common feature of such systems in quiescence .
Furthermore , the maximum in our folded lightcurve occurs at a different phase than observed before .