Deleted Subsite still referenced in Content DB

Hi,

I am currently having a few issues with errors from the SPHA on our SharePoint Foundation Server.

It was alerting that there are Missing Server Side Dependancies. Below (is an example of the SPHA error message)

Date and Time: 15/08/2012 17:07:16
Property Name Property Value
FilterValue Microsoft.SharePoint.Administration.Health.ContentDatabaseCorruption
Status ERROR
Explanation [MissingFeature] Database [Database] has reference(s) to a missing feature: Id = [448e1394-5e76-44b4-9e1c-169b7a389a1b]. The feature with Id 448e1394-5e76-44b4-9e1c-169b7a389a1b is referenced in the database [Database], but is not installed on the current farm. The missing feature may cause upgrade to fail. Please install any solution which contains the feature and restart upgrade if necessary.  [MissingSetupFile] File [Features\EPModules\_tsafix_AddEvent.xoml.wfconfig.xml] is referenced [1] times in the database [Database], but is not installed on the current farm. Please install any feature/solution which contains this file.

I have located what site the missing features are related to with the following SQL query

SELECT     dbo.AllWebs.FullUrl, dbo.AllWebs.Description
FROM         dbo.Features INNER JOIN
                      dbo.AllWebs ON dbo.Features.WebId = dbo.AllWebs.Id
WHERE     (dbo.Features.FeatureId = '448e1394-5e76-44b4-9e1c-169b7a389a1b')

This shows me the site that is missing the features (there are more in the error but they all relate to the same site)

It was seemingly caused by a migration into SharePoint Foundation from SharePoint 3 as the features all relate to PWS functionality. And these features whilst in the site data are not installed in SharePoint Foundation platform.

In order to resolve the alerts for the missing features we have removed the subsite that contained the missing features as it was not in use.

Strangely however SPHA is still alerting for the missing features and if I query the content DB I can see the features are still referenced in the AllWebs, AllDocs and Features tables.

Is there any way to forceably remove the references in the Content DB as even though the site is deleted it is still causing issues.

I assume that the Gradual Site Deletion task does not apply in this case as there is nothing in the SiteDeletion table or would this only apply to a deleted Site Collection?

If anyone could point me in the right direction as I cannot get rid of the alert and preferably I don't want to just ignore it.

Thanks

James