It will be a common mistake, to Alfresco One without the two additional war files that are required from 5-oh on. Or forgetting to map these additional wars in a frontend Apache server. Many Administrators will set up Alfresco as they have been used to until 5-oh.
This will cause Office to detect the server as an ordinary WebDAV enabled Web-Server, but not as a SharePoint server.
The problem is that MS Office stores this information in the Registry and does not query for the server type until a certain timeout.
This requires a registry cleanup on all client machines if Alfresco got accidentally deployed without its additional war files.
We can prevent this with a trick: Office does only store the server type if the path resolution has been successful. We only need to return the status code 404 when delivering the web page for a directory.
I strongly recommend this for the 5-oh HitList.