Ughhh, I just re-read that and realised it wasn't very clear, I edited my first line. It only happens (thankfully) when you export jpg animations, not when you export 2d graphics. I use this method so I can batch export perspectives, elevations, sections and plans from skp models which can take up to 30 minutes in total.
I'm not sure if font affects it (I just used Arial), but I suspect the two issues I mentioned are connected as it is the largest font (the "C") which moves out of alignment the most and the "horizontal copy" bug becomes more pronounced the larger the font size.