When editing a .doc file in a SharePoint document library, you need to always “check Out” when you see “Read Only”. You need to “Check In” the document after editing to TFS.
Figure: Warning - If you see “Read-Only” in the title bar, then you need to “Check Out”
Figure: Click “Check Out” to edit the document in TFS
Figure: When you click “yes”, expect a 2nd dialog - for SharePoint controlled docs
Figure: Good example – The dialog you should always get on saving