Chris,
I am using Power InRoads 08.11.09.872. I am displaying a new set of cross sections in a new model. The interval was set to 25' and it did not work. I created the section lines and imported from graphics and that also did not work. I am running the end area volume tool from the corridor menu. However, I was able to correct the issue by dragging the section line created by about .005' up or down station and re-importing from graphics.
Thanks,
Scott