What is going on with WordPress Stats?

 I clStrange WordPress Graphicked on my blog stats today and got this rather odd graph:



What does it mean?! What are Region A and Region B? And why were they doing something in 2003 – 2005 when my blog wasn’t even a twinkle in my eye?!

When I refreshed the graph went back to normal, but I’d love to know if anyone else has had something similar or knows why it might have happened.