I asked this question before, and after cleaning up the system in question, thought I had stumbled across the solution. No luck
Office 2013, Win 7 Pro, 2008 Server SMB simple File Shares (one user), Symantec Enterprise Edition
Word and Excel Files occasionally take FOREVER to open (minutes, not seconds)
PDF files never have this issue.
these account for the vast bulk (99%) of the file types this user accesses.