We have measured FMR at 9.4 GHz in bulk single crystal Ni samples for 20 < T < 380 °C. Up to 340 °C the data are consistent with temperature and frequency independent parameters. At higher temperatures analysis of the present results along with our previous measurements at higher frequencies, shows that none of the equations of motion is adequate. It is suggested that effects arising from fluctuations of the magnetization may be responsible for this failure