While the theory of single domain TRM has been very successful in describing qualitative behavior. It has been less so quantitatively. It is agrued here that at least some of the discrepancy between theory and experiment derives from inadequacies in the theory. An analytisis of the conventional dynamical model used in TRM theory in terms of the statistical mechanics of thermal fluctuations shows that it is internally inconsistent. Calculation of the distribution of thermal energy shows that, counter to the usual assumption, only a small fraction of the energy goes into producing uniform rotation of magnetization, suggesting that non-uniform modes are more likely to be the controlling factor in TRM. One possible non-uniform mode is suggested: reversal by passage of a domain wall through the grain.