Tiny text in every application (ie. tempo, title, lyrics)

I am using musescore version 0.9.5 on Vista. I have used it successfully many times in the past. Today, when I input music, I thought creating tempo text was not working. When I tried inputting lyrics, they came out so small that at first I thought they were not typing at all. That was when I realized the tempo text is also simply small. And so is the Title - almost invisible. Even where it says "piano" to the left of the page is tiny, tiny, tiny. I tried to change font size of the lyrics by using F2, but it said the selected text was already 11 point.

I need this for choir practice Wednesday. I don't want to input it again if I don't have to. I am running out of time.

Thanks for your help.