  We present exact spatio-temporal correlation functions of a Rouse polymer
chain submerged in a fluid having planar mixed flow, in the steady state. Using
these correlators, determination of the time scale distribution functions
associated with the first-passage tumbling events is difficult in general; it
was done recently in Phys. Rev. Lett.,101, 188301 (2008), for the special case
of "simple shear" flow. We show here that the method used in latter paper fails
for the general mixed flow problem. We also give many new estimates of the
exponent $\theta$ associated with the exponential tail of the angular tumbling
time distribution in the case of simple shear
