To get the Alfresco’s implementation of Sharepoint protocol to work properly on Vista/Office 2007 with NTLM authentication you need to mess a bit with your registry. I consider you did your job and are using fully updated versions of both Vista and Office.
Open up the Alfresco Share, navigate to the document library and locate some Office document and click Edit online. Likely, the file will open read-only. So, implement this fix from Microsoft’s article KB 870853.
If you try again, file will open up fine but when you save it you’ll get an error message stating “Word did not save the document”. To fix this stop or disable the Web Client Windows service using Services MMC snap-in.
Sharepoint protocol should work completely now.