SourceSafe Problem

Good Morning All

i have a Sourcesage Database created by me and my Boss has access to the Files in his Computer, now there is a Class Project that claims it has been checkout by him and when he checks in is Computer it says i have the file checkedout by me. Now another thing when he tries to checkitout from VS it says

"The File has been exclusively checkout by the same user in a different location"

We have delete any occurance of that file we have only in his machine. How can we overwrite this Error

Thanks