[chh]

Yes we tried that. Registry was clean after uninstall.
Manually registering the dlls like mentioned in this thread did not help.
Even uninstalled Outlook and reinstalled it.
"Best" we got was the error "Could not open your standard mail folder" (not sure about the translation) and Outlook exiting.
What I have seen is, that the old version was not cleanly uninstalled. We will try some ways of un-/instatll, upgrade... on some VMs with snapshots.

Update on first try: Uninstall old Connector, install new connector, manual re-registering of dll's. Result: Outlook crashesafter shortly showing some progress meter that could be from the connector, Outlook in safemode crashes, repair of Outlook starts, Outlook still crashes. So no success