VBA: Progress bar not showing

I'm running into a problem with a userform that I designed to be a progress bar. Basically, I put the code I wish to execute into the initialize event for the userform, and certain values on the userform are supposed to change as the code runs. However, while the code is executing (correctly), the area inside the form is just showing up as white. Everything's set to visible, and screenupdating is on. Does anyone know why this might happen? Is there some way to force it to refresh the view of the userform in the code?

Thanks to anyone who can help!