Make faces 1.4 with extruded objects

Hello,

Im using make faces 1.4 on a imported .dwg file of a city. The curb is a face wich i extruded so now i want to make a face of the road. This is where i get in to troubles : The tool wont make a face of the road. I guess the extruded curb next to it has something to do with the problem, since an other road with a non extruded curb works fine.

ill add my sketchup file for you guys so you can see for yourself.

P.S. Kinda new to sketchup and this forum. And English isn’t my first language i do apologize for posibble typo’s