@Andrew B well, of course AppleScriptTest.xojo_binary_project works, damnit. in fact everything works every step of the way except the share doesn't mount.
There must be an error generated. Look a Console. Chances are it is there.
After hours of messing around trying to get a simple apple script to work from my App (it always worked from script editor)
I eventually did the following and succeeded...
1 Wrote script in Script Editor
2 Tested script
3 compiled and saved script
4 QUIT SCRIPT EDITOR (or at least close the script..... this is the bit that had me going around in circles for hours!)
5 Drag script into xojo
6 Edit plist as suggested and drag into xojo
7 reset apple events from terminal using (not needed really)
8 run in debug and test
I still had the script open in script editor and was getting all sorts of 'violations' and fails in Console.