  A recently proposed solution of the `GSI anomaly' by spin precession of the
decaying heavy ions in the magnetic field that controls their circular motion
at the GSI storage ring [G. Lambiase, G. Papini, G. Scarpetta, PLB 718 (2013)
998, Ann. Phys. 332 (2013) 143] is dubious: the uncertainty in the computed
electron-capture decay-rate modulation frequency is at least of order 10E(7)
Hz, by far exceeding the 1 Hz modulation frequency reported in the GSI
experiment.
