A few questions about the Navigation Mesh stuff

Hey everyone,

I have been messing about with the Navigation stuff in Unity and am encountering some issues. My navigation mesh is a simple plane (no slopes or steps or anything) which moves around some buildings.

From some starting places, I am able to move the main camera to a set location using the Nav Mesh, but in some starting places, the camera will not move at all (i.e. cannot generate a path). What are the limits for the navigation system? Is there a maximum path distance Unity will work to? Should the mesh (imported from an FBX file) be modelled in a certain way to ensure the pathfinding system is happy?

I would appreciate any help with this :)

Jamie.