Hi Kevin 
to be in order to open it in cubase, I have to delete or modify the file plugin.prefs.
If not, I will get this little spark window that you could see. 
As I delete plugin.prefs, the registering window appear and I do register, and it works fine, until I close Cubase, the file plugin.prefs is modified and I know I will have to destroy it next time.
 
Tomorrow, I will test with a config cubase in 64 bits and I will tell you the result. 
 I have no other daw under hand.. 
If you need, I can send you the 4 files ".prefs"  inside my spark directory at the end of a session...
 
Regards
JP Pouyet