I'll take the no replies as the answer that nobody has a fix. I am willing to recompile the scenery using Instant Scenery and if John Hinson approves, would be willing to upload it to AVSIM as a special FSDT compatible version. (It will also be Megascenery Honolulu compatible - I have already reworked the AF2 file so it fits the photo scenery) I've already taken a look and all the objects that John used are available in the library.
But it would help if someone can tell me what actually caused the incompatibility so I'll know what I can and can't use. Can anyone help?
Ian