most likely, you need to embed your font. somewhat less likely, you need to change your font color so it's not the same color as your background.
Thanks for the response.
I did embed the font . . . though I selected only numbers as only numbers should appear. Is that reasonable? The color isn't the issue and the problem is intermittent -- sometimes I see the numbers and other I don't.
if the problem's intermittant, then you're probably loading from you cache (sometimes) and loading is so rapid, you're not seeing your preloader.