Timmo wrote:Ok let me know

Timmo, Ian - it's fixed. I am pretty sure I must have made the initial install without setting the FTX Central switcher to 'Default'.
What I did to fix it:
Timmo's advice about a modified Terrain.cfg rang a lot of bells. I had already found one, so I looked for others. I found a lot, so I moved every last one to a folder on my Desktop, to get them out of the way. (must remember to put the FS9 ones back)
Started FSX, and got a message that Terrain.cfg was missing or corrupt - Good! that proved there were no strays lying around.
Put the FSX Gold DVD Disk 1 into a networked machine, cancelled the install, and had a look at the files on the DVD.
Found terrain.cfg in FSX Disk 1:\program files\Microsoft Games\Flight Simulator X
Copied that file to my main FSX folder on the flying machine.
Checked FTX switcher was set to Default - got a message it could not access terrain.cfg (it was set to 'read only', because I had copied it from the DVD, not installed it)
Deleted VLC and VLC DTM from Scenery Library, then uninstalled as described in the VLC manual
Reinstalled VLC
Started FSX - Active runway at Rotorua - no weird shorelines or reefs !
Exited FSX, Changed Properties on terrain cfg from Read Only, set FTX switcher to AUstralia.
Started FSX, Active runway at Rotorua, still looking good, just the yellow houses.
Exited, redid the Oceania textures fix, back to Rotorua, no reefs and nice houses.
Since then, half-a-dozen or more switchings from VLC to FTX and back, no probs.
Many thanks for your help. The attachment tells its own story , I think. Notice the extended header info was not included in the FTX file.I am not favourably impressed with that.
Cheers
MikeW
[attachment=577:VLC__sho...ine_prob.txt]