The effect of long-range density fluctuations on the primary (alpha-) relaxation in poly(methyl-p-tolylsiloxane) BMpTS) was studied by means of light scattering. It is shown that the long-range density fluctuations (clusters) contribute only to the polarized (VV) and not to the depolarized (VH) correlation functions and make the system apparently nonergodic in the time scale of the alpha-process. Samples with different amounts of clusters were obtained by annealing at 55 degrees C for different time intervals in temperature jump experiments : +120-->+55-->-2.6 degrees C. The mean relaxation times and their distribution of the a-process obtained from the VH correlation functions (sample with clusters) and both VV and VH correlation functions (cluster-free sample) were equal and did not depend on the amount of clusters, indicating no coupling between the long-range density fluctuations and the primary alpha-relaxation.