Microsoft ForeFront may cause WCM deployment to fail

Today at a client site I noticed that content deployment just stopped working from my staging environment to the live site. Basically the job said that it failed, but gave no errors or warnings at the staging environment end. So I started to investigate what was going on within the destination server. The event log had the following error:

Failed import operation for Content Deployment job 'Remote import job for job with sourceID = f483830c-116d-4fd1-9d68-5dc6df9bd2cf'. Exception was: 'Microsoft.SharePoint.SPException: Exception from HRESULT: 0x81070000 ---> System.Runtime.InteropServices.COMException (0x81070000): Exception from HRESULT: 0x81070000
at Microsoft.SharePoint.Library.SPRequestInternalClass.AddOrUpdateItem(String bstrUrl, String bstrListName, Boolean bAdd, Boolean bSystemUpdate, Boolean bPreserveItemVersion, Boolean bUpdateNoVersion, Int32& plID, String& pbstrGuid, Guid pbstrNewDocId, Boolean bHasNewDocId, String bstrVersion, Object& pvarAttachmentNames, Object& pvarAttachmentContents, Object& pvarProperties, Boolean bCheckOut, Boolean bCheckin, Boolean bMigration, Boolean bPublish)
at Microsoft.SharePoint.Library.SPRequest.AddOrUpdateItem(String bstrUrl, String bstrListName, Boolean bAdd, Boolean bSystemUpdate, Boolean bPreserveItemVersion, Boolean bUpdateNoVersion, Int32& plID, String& pbstrGuid, Guid pbstrNewDocId, Boolean bHasNewDocId, String bstrVersion, Object& pvarAttachmentNames, Object& pvarAttachmentContents, Object& pvarProperties, Boolean bCheckOut, Boolean bCheckin, Boolean bMigration, Boolean bPublish)
--- End of inner exception stack trace ---
at Microsoft.SharePoint.Library.SPRequest.AddOrUpdateItem(String bstrUrl, String bstrListName, Boolean bAdd, Boolean bSystemUpdate, Boolean bPreserveItemVersion, Boolean bUpdateNoVersion, Int32& plID, String& pbstrGuid, Guid pbstrNewDocId, Boolean bHasNewDocId, String bstrVersion, Object& pvarAttachmentNames, Object& pvarAttachmentContents, Object& pvarProperties, Boolean bCheckOut, Boolean bCheckin, Boolean bMigration, Boolean bPublish)
at Microsoft.SharePoint.SPListItem.AddOrUpdateItem(Boolean bAdd, Boolean bSystem, Boolean bPreserveItemVersion, Boolean bNoVersion, Boolean bMigration, Boolean bPublish, Boolean bCheckOut, Boolean bCheckin, Guid newGuidOnAdd, Int32& ulID, Object& objAttachmentNames, Object& objAttachmentContents, Boolean suppressAfterEvents)
at Microsoft.SharePoint.SPListItem.UpdateInternal(Boolean bSystem, Boolean bPreserveItemVersion, Guid newGuidOnAdd, Boolean bMigration, Boolean bPublish, Boolean bNoVersion, Boolean bCheckOut, Boolean bCheckin, Boolean suppressAfterEvents)
at Microsoft.SharePoint.SPListItem.Update()
at Microsoft.SharePoint.SPAttachmentCollection.AddNow(String leafName, Byte[] data)
at Microsoft.SharePoint.Publishing.Administration.JobReportBase.Update()
at Microsoft.SharePoint.Publishing.Administration.ContentDeploymentJob.importexport_Error(Object sender, SPDeploymentErrorEventArgs errorEventArg)
at Microsoft.SharePoint.Deployment.SPDeployment.OnError(SPDeploymentErrorEventArgs e)
at Microsoft.SharePoint.Deployment.DeploymentLogger.Log(DeploymentLogSeverity severity, SPDeploymentObject deplObject, String message, Boolean throwException)
at Microsoft.SharePoint.Deployment.DeploymentLogger.Log(DeploymentLogSeverity severity, SPDeploymentObject deplObject, Exception exception, Boolean throwNewException)
at Microsoft.SharePoint.Deployment.DeploymentLogger.Log(DeploymentLogSeverity severity, Exception exception, Boolean throwNewException)
at Microsoft.SharePoint.Deployment.SPImport.Run()
at Microsoft.SharePoint.Publishing.Administration.ContentDeploymentJob.DoImport()'

This would be a tricky one to fix...
So I dug deeper into the event log and noticed that a couple of days before, when there were no errors, this service called GetEngineFiles (i.e. ForeFront) had been started. The service was having numerous problems accessing the internet to updated its various scanning engines (because it was a dev machine, and external web access was blocked by the proxy). So I walked over to the infrastructure guys and politely asked 'What the F@#% have you been doing with my server?'. To this they responded 'oh, we installed Microsoft Forefront on it a couple of days ago and configured SharePoint to integrate with it'. So I again politely asked for them to uninstall it and reboot the machine. After this, miracles of miracles, the WCM deployment started working again.
There endith the lesson - Without communication, we would all be lost!