We have mutliple problems when upgrading Agents on Windows 7 x64 (fr or de).

Sometimes it just failed (either "requirements" are not meet.... or "msi engin in use..." --> maybe in the next version the agent updater will check the use of msi engine before attempting to update??)
Sometimes it success but user cannnot log into the zone anymore. We have to do zac retr or reinstall CASA.x86_64.msi and authtokenclient.x86_64.msi. Can it be because we also use Novell Client 2 SP2/3??

Sometimes it is just impossible to uninstall the adaptive agent! And worst, sometimes it just breaks the Windows installation when trying to uninstall (no reboot is possible)!

ZCM is a great product but we lost a lot of times troubleshooting things that just must work with confidence.