Temporally two-dimensional impulsive stimulated Raman scattering can be obscured by various artefacts such as interfering or sequential third-order processes, scattering due to hyperpolarizabilities, and higher-order Bragg diffraction. These effects can modify the observed signals, depending on the employed beam configuration. However, they cannot explain the observed discrepancies between current theories and experimental results for neat carbon disulfide. (C) 1997 Elsevier Science B.V.