Acrobat Pro - Locking Files on Windows Server

We have opened a case with MS about being unable to delete files on the network as it says it is in use.  Since it is only PDF files they are saying it is a Adobe issue.

We do the following:

Open document insert and save............cannot delete

Preview document.........can not delete

Open document and close.........cannot delete

Open document organize pages save........cannot delete

Also, cannot rename the file sometimes. 

All the above only happens sometimes not every time we go into a file

Windows says it is use by explorer and under files in use on the server, it shows in use by the user for hours.