Well, you're jumping from one point on the map to another. The engine has no time to load all the objects and textures for the new scene. Without giving the engine some time your problem can't be solved.
You could try something like this:
1. Blank the screen and create the camera
2. Use camPreload without a timeout
3. Wait until it's done
4. Use preloadCamera on the next location (let's call it "Scenery2")
5. Show current scenery until preloadCamera for "Scenery2" is done
6. Use preloadCamera on the next location (let's call it "Scenery3")
7. Show "Scenery2" until preloadCamera for "Scenery3" is done
6. Use preloadCamera on the next location (let's call it "Scenery4")
7. Show "Scenery3" until preloadCamera for "Scenery4" is done
This might ruin your timings, however, since you cannot tell how long it will take the engine to preload stuff.
Another approach would be to blank the screen, preload all locations, pray that the user has enough RAM to store the whole stuff, wait until all locations are preloaded and continue.