They have spoken on this previously.
Here's a thread with the owner helping someone with multiple activations a couple years ago
http://www.pgmusic.com/forums/ubbthreads.php?ubb=showflat&Number=278148&page=2

I'm sure you can find more using search.
The official word at the time was; 3 computers can be activated (have the program installed).
You can use one at a time.


Make your sound your own!
.. I do not work here, but the benefits are still awesome