  We address the question of the effect of disorder on heat conduction in an
anharmonic chain with interactions given by the Fermi-Pasta-Ulam (FPU)
potential. In contrast to the conclusions of an earlier paper [Phys. Rev. Lett.
86, 63 (2001)] which found that disorder could induce a finite thermal
conductivity at low temperatures, we find no evidence of a finite temperature
transition in conducting properties. Instead, we find that at low temperatures,
small system size transport properties are dominated by disorder but the
asymptotic system size dependence of current is given by the usual FPU result J
~ 1/N^{2/3}. We also present new interesting results on the binary-mass ordered
FPU chain.
