I found a couple of airports during SU10 beta that are also flat and, as I stated in my initial report above, I do not feel this is an SU11 issue.
When I filled out the reports for the two airports during SU10 beta, one of them was moved by the moderators to the SU10 beta bug report section, because it was the beta’s version number that I used under the standard non-beta bug report form’s “Build Version # when you first started experiencing this issue:”. For some reason the other airport escaped being moved.
I just stuck this bug here, because I figured they’d do that again. Again, I think all three of these flat airports were probably flat before both SU11 and SU10 beta.