Report Server - SharePoint: IReportViewerMessages or could not be found

If you have Report Server running in a virtual directory under a SharePoint web app.

Error: The type Microsoft.SharePoint.Portal.Analytics.UI.ReportViewerMessages, Microsoft.SharePoint.Portal, Version=12.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c does not implement IReportViewerMessages or could not be found.

Cause: Look in your SharePoint web.config file you'll see
<add key="ReportViewerMessages" value="Microsoft.SharePoint.Portal.Analytics.UI.ReportViewerMessages, Microsoft.SharePoint.Portal, Version=12.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" />.

Fix: I looked at the Microsoft.SharePoint.Portal.Analytics Namespace and couldn't find a UI.ReportViewerMessages, so I just removed it from the web.config and I haven't experienced any issues.
You can also remove the setting from your ReportServer web.config's just add:

<appSettings>
 <remove key="ReportViewerMessages" />

</appSettings>