Symantec touching files even with exclusions set?

We have an exclusion set for F:\Imagenow and all subdirectories in Endpoint Protection.  I see the exclusion in HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Symantec\Symantec Endpoint Protection\AV\Exclusions\ScanningEngines\Directory\Admin.   However, on the server we see ccSvcHst.exe (Symantec) touching a ton of files in the F:\Imagenow directory.  Our onsite Symantec support tells us that "Symantec touches the files anyway even though the exclusion is set".  It is using 4x the disk IO of our application!  Is this statement correct or have they configured the exclusion wrong?