Hi Nigel. Thanks for the quick reply. I am running 10.1 and I just e-mailed for the newest release.
As it happens, I have made some changes to the structure of my application and the LayersMege call is now working. I have absolutely no explanation. I'll just keep my fingers crossed that the problen is solved permanently.
If you are using a TImageEnLayerMView there were situations where list index issues might occur, plus some other less common occurrences in TImageEnView. I expect that 10.2.0 will resolve them for you.