333 cm-1 is corresponds to (E2high - E2low), whereas 437 cm-1 is E2high vibrational mode and 101 cm-1 E2low. In general, 333 peak comes with very low intensity compared to 437 one. At this moment, I cant say about the special significance of that peak but if you want to check the quality of the sample, then 101 and 437 peaks are the significant because these two are the characteristics of ZnO wurtzite structure.