Bug in HEC-RAS cross section flipping?

Fellow HEC-Users-

I have run into a problem with the HEC-RAS geometry editor. I imported a HEC-2 model into HEC-RAS 2.2, made a few minor changes to some bridges, and ran the model successfully.

I then saved a copy of the entire project to a different folder, and then flipped the cross section geometry end for end for all of the cross sections. I saved the modified geometry file and tried to run the model, but it crashed and gave me an error message at every cross section saying that the Manning's "n" value for the left overbank was not set.

As a check, I flipped the geometry on one of the example data sets that comes with HEC-RAS. I got the same crash and error messages.

Any ideas what may be causing this problem? Is there a program bug?

Thanks,
Chris Hauser, P.E.
chris.hauser@fpsengineering.com