Forum:Utau not working

ok, i got utau and the first time i used it it worked fine. i could enter in stuff and the sounds played fine, (i was using defoko) but the second time i tried to open the program and use it when i tell anything i put in to play it doesn't. i checked my speakers and i dont know whats wrong no matter which one of the utaus i've downloaded defoko, momo, mako, none of them work however the utau im making works without a problem, i also tried giving aliases to the sounds in their voicebanks incase that was the problem, and that hasn't changed a thing.