I just bought Beyond The Sword today.

One of the first changes I've noticed is that my national borders now have a diagonal line pattern amongst them. Before BTS playing as the Americans for example, I would have a blue line around my national borders. In BTS that same border exist but my entire nation also has diagonal blue lines running through the "entire" empire.

It is really distracting and garish. How can I turn that off so that I just have the Blue line around the edge of my civilization and not the diagonal stripes through my whole land?

It sounds like the pattern that appears when you've selected a settler, but I don't know why it would stay after you settled a city... could you please post a screen shot of the problem?