  In a recent Letter of Gorny et al. it was reported that the spin-lattice
relaxation rate in YBCO_{7-d} is magnetic field independent. These authors
point out that their results are inconsistent with prior reports of Borsa et
al., Carretta et al., and Mitrovic et al., which concluded that there is a
small but significant magnetic field dependence. In this comment we propose an
explanation for this discrepancy.
