In this paper we discuss some methods used by several authors (Saito, 1979; Quabili and Karasulu, 1979) to solve stochastic point-reactor kinetic equations with a non-white noise. In order to test the validity of these methods a simple exact model without delayed neutrons is considered. The main point of the paper concerns the validity of the causal relation, which is shown not to hold when the noise is a non-white external one. It is shown that the equation obtained by Saito (1979) for the mean power is valid for weak noises. Adversely, the equations obtained by Quabili and Karasulu (1979) for the mean, variance and correlation function of the power reactor, are shown to be inconsistent as regards the non-Markovian terms.