I'm sure this is probably covered in some obscure note in the VSOM Guide somewhere, but it's likely not too prominent. It's by design! Super awesome, eh?
So yeah, what you are seeing is how Cisco has arranged the licensing. Apparently, you can use the 'free' licenses up to the limit of 10... unless you want to exceed that with 3rd Party HW, at which point, you need to license *ALL* 3rd Party and anything that was previously free goes away :-/
Scott Olsen
Solutions Specialist
Bulletproof Solutions Inc.
Web: www.bulletproofsi.com