Did you change the locale on your machine by chance? The code for checking this is rather simple, and it's all done locally (no time server). Somehow, VoiceAttack is thinking you had started it at one date/time and then started it again prior to that date/time.
Unfortunately, I don't have a way to restart or change the trial and there is not much more I can suggest to you, other than to log in as another user on your machine. Sorry about that!