We are seeing the following error over and over again in the event viewer.  It shows up every 30 seconds. We are running version 7.3.1 and have 2 web servers that are reading from a central file server.  The ip address in the error below belongs to that file server.  The site is setup in IIS with the "Physical Path Credentials" set for access to the file server and if I browse to the folder mentioned in the error and look at the Security settings, the user used in IIS has "Full Control" over this folder.  

DefaultDataProvider:DotNetNuke.Data.SqlDataProvider, DotNetNuke

ExceptionGUID:e743591e-c10c-48b2-80fa-d9d604e2cf2c

InnerException:Access to the path '\\(removed).228.208\StageWeb\Portals\2-System\Cache\Pages\' is denied.

FileName:

FileLineNumber:0

FileColumnNumber:0

Method:System.IO.__Error.WinIOError

StackTrace:

Message:

System.UnauthorizedAccessException: Access to the path '\\(removed).228.208\StageWeb\Portals\2-System\Cache\Pages\' is denied.
   at System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath)
   at System.IO.Directory.InternalCreateDirectory(String fullPath, String path, Object dirSecurityObj, Boolean checkHost)
   at System.IO.Directory.InternalCreateDirectoryHelper(String path, Boolean checkHost)
   at DotNetNuke.Services.ModuleCache.FileProvider.GetCacheFolder(Int32 portalId)
   at DotNetNuke.Services.ModuleCache.FileProvider.PurgeExpiredItems(Int32 portalId)
   at DotNetNuke.Services.ModuleCache.PurgeModuleCache.DoWork()