Grading will not create surface

[randcdavidson]

I have two seperate graded levees in my drawing. One has created a surface just fine, the other absolutley refuses to generate a surface. I've deleted the grading even the feature lines and re-did them. In my grading group I have automatic surface creation checked and the voulme base surface checked. I show the surface in the prospector but there is nothing there. The one levee will show contour styles but this one ZIP!

What is going on?

[randcdavidson]

Did a little manipulating of my featurelines. I created another levee just like the one that won't surface. I moved the new levee featurelines close to the same pi's as the bad one. I can get all new pi's close to old ones excpet the two on the end. As soon as I close in (within a few feet) the surface deletes itself.

[Joe-Bouza]

How was the base feature line create? Are there other feature line in the drawing possibly in the same site?

View the FL in elevation editor: Are there any split points or an unusual number of shared points?  are ther any out of limit elevations? does the surface build parameter have any restrictions i.e. dont use elevation greater or less than?