No sound during playback

Yay, it's me again.
Whenever I open Utau and use the pencil tool to make a new note, then play it, there's no sound. I don't know if this is just my computer, or an issue with the particular version of Utau...? (I didn't have this problem until I installed the latest version of Utau. Now I get the problem no matter which version I'm running; I tried uninstalling it and installing older versions, but I still get the problem.) I also get no sound during playback when I import a MIDI file.

I thought it was just an issue with my speakers, or my headphones, but it's not, I'm still getting sound from other programs. It seems to just be Utau. :T

S-so, help, anyone? ;A;