Notice 1: Setting the same line at MainDemoWindow.cpp:42 (just at the end of the ContentComp Ctor) prevents this issue and displays the fonts just fine.
Notice 2: In my application the distortion is a little different. The fonts are generally skinnier and the bold letters are corrupted:
Ok, I had a look at this. The problem is because you're switching the default font while the program's already running. There's a cache which stores recently-used glyphs, and that will already contain cached versions of characters from the old font that had been drawn before you changed it. Because the default font uses a special symbolic name rather than a typeface name, the cache doesn't realise that it's different, so the old characters still get used for a while. Easy enough to fix, I'll just make sure it flushes the cache when you set the global font!