I've been getting an error when generating object LOD in the CK, saying some objects were rejected becasue they were "under landscape." Some of the objects are halfway under the landscape, but some aren't even touching it. Has anyone else encountered this problem, or has a way around it?

Nvm, figured it out. If you generate textures and Distant terrain/meshes then generate Object LOD right after without saving or closing the CK, it will work since generating textures and terrain flattens the landscape. Close out of the CK without saving and you'll have your landscape back.