PDF's open slowly or "Not Responding" from XP Pro desktop shortcut to SMB server

I have a Toshiba copier that scans documents as PDF's.  They are stored on an internal hard drive that is shared via Linux based SMB as "File_Share" in a subfolder ("SCAN") which is created each time a document is scanned.  There is no security set on the Toshiba share.  I have 10 people accessing this File_share to retrieve their scanned documents through shortcuts created on their desktops.  Nine of them work perfectly.  I have one guy who continually experiences slow-to-open or "Not Responding".  More bizare, if I logon to his computer as a network administrator, create the same shortcut and open a PDF it opens instantly.  I have verified security for the user through the shortcut and it is the same as an admin.  By the way, the user is an admin on the local machine.  I have nuked the shortcut and rebuilt new ones, still same problem.  I have uninstalled and re-installed Adobe 9, still same problem.  The environment is a Windows domain running Windows 2k3 servers with internal DNS.  All users are runnning Win XP Pro.  Any suggestions are welcome.