copy-datastoreitem ERROR : Unable to write data to the transport connection: An established connection was aborted by the software in your host machine

Hi, I've had this error on one of your vcenter servers.when trying to upload files via powercli or via curl, both use http POST I believe.

PS D:\Users\myuserid> Copy-DatastoreItem D:\filename.iso $ds.DatastoreBrowserPath -Recurse

Copy-DatastoreItem : Upload of file 'D:\adam.iso' failed. Error message: Unable to write data to the transport connection: An

established connection was aborted by the software in your host machine.

At line:1 char:1

+ Copy-DatastoreItem D:\filenameiso $ds.DatastoreBrowserPath -Recurse

+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

    + CategoryInfo          : NotSpecified: (:) [Copy-DatastoreItem], VimException

    + FullyQualifiedErrorId : Client20_StorageServiceImpl_UploadFile_UploadFailed,VMware.VimAutomation.ViCore.Cmdlets.Commands.CopyD

   atastoreItem

This was working up until about 3 weeks ago ! Uploading via the vcenter client is working fine.

vCetner 4.1.0 build 345043

filename.iso is only 6MB in size.

It's logged with VMware but don't seem to be getting anywhere with it, help appreciated.