The only thing that it's sure, that it can't be related in any way to KLAX 1.1, because ntdll.dll it's a generic memory allocation crash, which is not related to the scenery system, and if it's happening at all airports, it can't be created by KLAX, not that 1.1 should make any difference compared to 1.0 in this regard.
The only modification the installer does to the FSX.CFG is enabling 4066x4096 textures, buy if you change it to 1024, it will be just like default (KLAX will look blurred, of course).
If you uninstall the scenery and reply YES to the questions "Do you want to remove the Addon Manager ?" and "Do you want to remove the Couatl engine ?" which are made at the end, it will be exactly as if KLAX was never installed so, if you are still getting the ntdll.dll crash, you can be sure it's nothing related to KLAX.