End Area Volumes in Cross Sections

I have 2 sets of cross sections recently where I needed to get volumes from my cross sections that are cut at 50' intervals.  Ocassionally I have had to hand end the cross sections to change a particular cut or fill or if for some reason the components don't display properly.  It seems that sometimes when I do this and then try to compute the volumes I will get volumes that extend in the sheet up or down one or two stations and then intercept the except the existing surface giving me a completely wrong volume calc.  I have tried to see if some component wasn't fully closed and also went back in and reconnected.  Would copying a component from another station (like copying a regular curb component) and pasting it in the cross section that wasn't displaying correctly give me this problem?  I have attached a picture of whats happening.

 MS: 8.05.02.70
inRoads: 8.08.00.46

Thanks,

neal