Most of the WORDS on the screen, such as "File, View, Help", etc at the top, as well as most of the rest, are simply rows of boxes, not letters. By guessing what they are, I can download okay, but what is causing them to display this way?

I used the free version (3.6.15) with no trouble, but last week I upgraded to the latest version 4.0.7 Pro, and that's when I lost the screen characters.