Running two webheads on NLB. I have five instances of DNN running and each one is failing to complete the scheduled task of: "DotNetNuke.Services.Cache.PurgeCache, DOTNETNUKE".

I'm getting desperate trying to figure out why I get this exception:

AssemblyVersion: -1
PortalID: -1
PortalName:
UserID: -1
UserName:
ActiveTabID: -1
ActiveTabName:
RawURL:
AbsoluteURL:
AbsoluteURLReferrer:
UserAgent:
DefaultDataProvider:
ExceptionGUID:
InnerException: Access to the path '\\tpa2-adm-001\egovt01\Portals\_default\Cache\TW9kdWxlUGVybWlzc2lvbnM3Mw==.resources' is denied.
FileName:
FileLineNumber: -1
FileColumnNumber: -1
Method:
StackTrace:
Message: System.UnauthorizedAccessException: Access to the path '\\tpa2-adm-001\egovt01\Portals\_default\Cache\TW9kdWxlUGVybWlzc2lvbnM3Mw==.resources' is denied. at System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath) at System.IO.FileStream.Init(String path, FileMode mode, FileAccess access, Int32 rights, Boolean useRights, FileShare share, Int32 bufferSize, FileOptions options, SECURITY_ATTRIBUTES secAttrs, String msgPath, Boolean bFromProxy) at System.IO.FileStream..ctor(String path, FileMode mode, FileAccess access, FileShare share, Int32 bufferSize, FileOptions options) at System.IO.StreamWriter.CreateFile(String path, Boolean append) at System.IO.StreamWriter..ctor(String path, Boolean append, Encoding encoding, Int32 bufferSize) at System.IO.StreamWriter..ctor(String path, Boolean append) at System.IO.File.CreateText(String path) at DotNetNuke.Services.Cache.FileBasedCachingProvider.FBCachingProvider.CreateCacheFile(String FileName) at DotNetNuke.Services.Cache.FileBasedCachingProvider.FBCachingProvider.Insert(String CacheKey, Object objObject, CacheDependency objDependency, DateTime AbsoluteExpiration, TimeSpan SlidingExpiration, Boolean PersistAppRestart) at DotNetNuke.Common.Utilities.DataCache.SetCache(String CacheKey, Object objObject, TimeSpan SlidingExpiration, Boolean PersistAppRestart) at DotNetNuke.Security.Permissions.ModulePermissionController.GetModulePermissionsDictionary(Int32 TabId) at DotNetNuke.Security.Permissions.ModulePermissionController.GetModulePermissionsCollectionByModuleID(Int32 ModuleId, Int32 TabId) at DotNetNuke.Entities.Modules.ModuleController.FillModuleInfo(IDataReader dr, Boolean CheckForOpenDataReader, Boolean IncludePermissions) at DotNetNuke.Entities.Modules.ModuleController.FillModuleInfoCollection(IDataReader dr, Boolean IncludePermissions)
Source:
Server Name: TPA1-WEB-004

The permissions are correctly set up to allow the Network Services access to the Cache folder. Is there another process that needs access??

Somehow I read the WebFarm Support document to read that the purgeCache process had to be run by each web server. Now I re-read it and I don't see that at all. Thank you for clarifying I will try it on only one server.

The other thing I wonder about is that when I enable FileSystem.SynchronizeFileSystem on the scheduler it fails as well.

(I hope this post is readable, I can't even see the errors I posted in IE7!)

thank you for the response! I made sure that the task is only running on one server and am still getting these errors: 

 the tpa2-adm-001 is the file server for the UNC shares, these are on a domain and the website accesses the UNC share thru a domain user permission. Further, the Network Service is the owner of the app pool. I even tried making the permissions on the cache folder available to "everyone" but still get this error. I read 'Access to the path' as a permission error, am I on the wrong track?