Getting the following error to show up once an hour.  Does anyone have any idea where this problem might be coming from?  I'm having trouble coming up with anything from a search.

THREAD ID: 11
TYPE: DotNetNuke.Services.FileSystem.SynchronizeFileSystem
EXCEPTION: Object reference not set to an instance of an object.
RESCHEDULED FOR: 5/1/2007 1:21:23 PM
SOURCE: STARTED_FROM_BEGIN_REQUEST
ACTIVE THREADS: 0
FREE THREADS: 1
READER TIMEOUTS: 0
WRITER TIMEOUTS: 0
IN PROGRESS: 0
IN QUEUE: 11
Server Name: DNNWEB1

Any help would be greatly appreciated.

Thank you.

I have the same problem in DNN 4.1.1. When I restart my portal from Host --> host settings all my portals lose their connection to their root directory. Many of them have the logo file in the root and the result is no logo file is shown on the site. I have to manually define it for every portal.
Se below the exception in my event log.

Any help on this?
/Sten

AssemblyVersion: -1
PortalID: -1
PortalName:
UserID: -1
UserName:
ActiveTabID: -1
ActiveTabName:
RawURL:
AbsoluteURL:
AbsoluteURLReferrer:
UserAgent:
DefaultDataProvider:
ExceptionGUID:
InnerException: Object reference not set to an instance of an object.
FileName:
FileLineNumber: -1
FileColumnNumber: -1
Method:
StackTrace:
Message: System.NullReferenceException: Object reference not set to an instance of an object. at DotNetNuke.Services.FileSystem.FolderController.GetMappedDirectory(String VirtualDirectory) at DotNetNuke.Entities.Portals.PortalInfo.get_HomeDirectoryMapPath() at DotNetNuke.Services.FileSystem.SynchronizeFileSystem.Synchronize() at DotNetNuke.Services.FileSystem.SynchronizeFileSystem.DoWork()
Source:
Namn på Server: WEB01