I have a document library with a workflow and content type attached to it. When you select new, word is opened with the custom content type. When I save the file it says that this file is checked out and I have to check in when I want to do this it asked for the version, but I cannot checkin. We have several users, which are working without any problems on the same document library. It's just the users, which have Office 2010 cannot save and start a new workflow.

With Office 2007 we do't see any issues.