Thanks Scott Y,
I found a simple solution: Upgrading to 7.1
Here are the details:
On LV7.0 and Win2000: If you start a LV-application (exe) and start the same exe again, the first instance comes to front (no new instance is opened). If you start the exe a third time then a new instance is created. Why? I have no clue.
I finally upgraded to 7.1 (after the CD has been sitting in my drawer for about a year) and now this strange behaviour disappeared. There must have been a change in the runtime engine or something.
In short words: apps compiled with LV7.1 App.builder can only be started once - that's exactly what I wanted.
-DB
