I am running dnn 4.01 and dnn 3.1 on SQL 2000 with IIS 6.0.   I have 2 web server that are clustered attached to 1 sql server.  My dnn 4.01 installation has about 15 parent portals and my dnn 3.1 installation has 1 portal. 

I have read through the dnn web farm support documentation and I am not sure what is going on with my dnn portals on both installes.  I have used the dnn web farm support documentation to configure my servers for web farm support and spent much time researching the setup of dnn clustering. I am using file replication from 1 server to another, meaning 1 dnn install for each version, on each server where the file structures are the same, and not 1 storage area.  The sites are running very slow.  When I check my log viewer I am getting the following error messages:

Message 1

InnerException: Object reference not set to an instance of an object.
Message: System.NullReferenceException: Object reference not set to an instance of an object. at DotNetNuke.Services.FileSystem.FolderController.SetMappedDirectory(String VirtualDirectory)

Message 2

InnerException: Unhandled Error:
Message: System.Exception: Unhandled Error: ---> System.Web.HttpException: Not Found at DotNetNuke.HttpModules.UrlRewriteModule.OnBeginRequest(Object s, EventArgs e) at System.Web.HttpApplication.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) --- End of inner exception stack trace ---

PLEASE ADVISE???