COMAND Navi avoid HOV roads
 

I got my 2008 E350 with COMAND Navigation in Dec 07. I realize that the system avoids all highway with HOV lane. If I drive on one, it says "Time Restricted Road" and keep directing me to leave the highway although I have "Avoid highway" off. We have many HOV road in the Metropolitan DC area. This problem makes the navigation system quite useless.

I look up the COMAND manual and am unable to find a way to fix this problem. Did I miss anything? Please help.