mtnhntr

I just installed the navigation SD card in my Audio 20 system. Works great, except that the speed limit display appears to be in kilometers per hour while every thing else is displayed in normal USA terms (Speed in MPH, Distance in miles, etc.). The speed limit indicator is the only thing in metric. I can find nothing in the menu that would change this item. The SD card is Mercedes part # A2139062704 and is version 5.2 which seems to be the latest on the Mercedes USA website.
Can any of you that have this navigation tell me if yours is the same, or tell me how to change it? Or is this another conspiracy to get us into the metric system.
Thanks in advance!