Upgrade ZA8 -> error installing antivirus drivers --> post install procedure blank window
clean install ZA9 -> error loading vsutil -- procedure not found (more or less)
install VC++ 2008 SP1 redist
clean install ZA9 --> error loading vsutil 64 bits
re install again --> success !! (however, post-install procedure creates a blank window)
restore settings -> seems to work (BTW did you notice you cannot back-up ZA settings if you change your "documents" folder location ?)

since then running OK although truevector uses 30% to 40% of a E8400 dual core intel while emule is running.

I understand ZA won't propose yet an immediate upgrade to version 9 :-)