Eset Outlook addin causes unnamed folder to appear.

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I'm using eset Endpoint Antivirus v.6.1.2222.0.  I have several users using Outlook 2010 that have what appears to be a unnamed top level folder.  Sometimes there are email messages in this folder.  If you right click on the folder, it shows a name of <0w#25> (see screen capture attached).  It can be deleted but it is recreated as soon as any message is opened. 

 

This appears to be caused by the Eset Outlook addin.  Disabling the addin and deleting the folder results in it not returning.  As soon as I reenable the addin, the folder comes back.

 

Doing a Google search on this mystery folder finds some talk of a corrupt .pst file.  I have tried using scanpst several times but nothing works except to diable the Eset addin.  Anyone have any idea what's going on?