Follow up to my earlier post with artifacts problem.
When I tried to load the same file (I burned it to CD at work) when I got home, it reported corruption and would not load. Downloaded again, and all seems OK.
Thanks to Wictor for the PDA map. Lovely.
The scale of this scenery is amazing. Set a few waypoints for a little look around. Found I had actually set a 150k task instead of the 50k I had thought ! Wow
Thanks to all.