Asymmetric quantum dots (QD) provide non-bleaching probes of the rotation of individual cell surface proteins. We have conducted imaging measurements of individual 2H3 cell Type I Fce receptor rotation on timescales down to 10 ms per frame. We have also used time-tagged single photon counting measurements of individual QD to examine μs timescales, though such rapid timescales are limited by QD emission rates. In both approaches we calculate the time-autocorrelation functions (TACF) for fluorescence polarization fluctuations. Decays of these fluctuations extend into the ms timescale, as implied by time-resolved phosphorescence anisotropy results. Effects of cell treatments such as receptor crosslinking suggest that this slow decay may be a property of the membrane itself, perhaps reflecting large-scale fluctuations of mesoscale membrane regions. However, depending on instrumental parameters used in data analysis, polarization fluctuation TACFs can contain a contribution from the intensity fluctuation TACF arising from QD blinking. Such QD blinking feed-through is extremely sensitive to these analysis parameters which effectively change slightly from one measurement to another. We discuss approaches based on the necessary statistical independence of polarization and intensity fluctuations to guarantee removal of a blinking-based component from rotation measurements. Supported by NSF grant MCB-1024668.