A couple of additional thoughts.....
It has been reported by several users that VE PRO 4 does not have this ASIO Guard 2 problem.
I can say in my giant template when I switch from various non-VE PRO 5 instrument tracks I do not have any delayed sound issues at all.....only when switching to or from various VE PRO 5 instruments. Switching to different midi tracks on the same VE PRO 5 instrument is fine, the problem happens when you switch do a different VE PRO 5 instantiation.
Another major issue when I have ASIO Guard 2 on is that I get huge 100% ASIO spikes often when a tempo change happens. I still think this is related to something in VE PRO 5 as many of us have discussed tempo change problems that cause CPU spikes when using Cubase/VE PRO 5/and usually Kontakt.
Hopefully they can get this sorted out soon.