I can't say precisely, but I suspect it has to do with the way the low-level drivers are done. In LV with drivers that take the form of some type of external code (CIN, DLLs, etc) there is code that runs when you execute the VI calling it, and some code that executes when you load the driver into memory. Typically this load-time behavior is things like initializing memory, setting up memory structures it will use, and that sort of thing.
The long and the short of it is that you will have to design your hardware such that any operations that happen at startup don't have unintended and undesired effects.
Mike...
