The authors of an earlier paper [Opt. Lett. 32, 3558 (2007)] reported two "ambiguities" in second-harmonic-generation frequency-resolved optical gating (FROG). One ambiguity is simply wrong--a miscalculation. The other is well known and easily avoided in simple well-known FROG variations. Finally, the authors' main conclusion--that autocorrelation can be more sensitive to pulse variations than FROG--is also wrong.