TFS lock checking

Im working my way through an unusual TFS issue:
The item $//Security/Security.vsd is locked for check-out by (null) in workspace (null).

The problem appears to be a changed workspace while the item was checked out.

Thanks to James Manning for the following command line check:

tf lock $/MyProject/MyPath/MyFile.cs /lock:none /workspacename:WorkSpaceName /server:my_server

The easiest fix is to get the other workspace(s) with pending changes to either undo or checkin their changes. You can see who has pending changes with:

                Tf status /user:* $/Security/Security.vsd /server:my_server

I also found, whilst doing researchon the issues, some excellent TFS top tips here: