It has been recently shown that the presence of large amplitude left-hand polarized waves can change the linear properties of ion-beam plasma electromagnetic instabilities <Gomberoff, 2003>. Thus, it was shown that in the presence of large amplitude Alfv¿n or ion-cyclotron waves, linear beam-plasma right-hand polarized instabilities tend to be stabilized. In particular, when the nonlinear wave amplitude exceeds a threshold value, the linear instability can be completely stabilized. Here, by using computer simulation techniques based upon a one-dimensional hybrid code, we confirm these results.