Sharepoint won't display homepage in portal... :(

[PortalNewb]

Hey guys,

I'm getting the following error when we try to go to the homepage of our internal portal. Does anyone have any thoughts on why we're getting this exception??


Server Error in '/' Application.
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The 'WpNs0' prefix has already been mapped to a namespace.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: Microsoft.SharePoint.WebPartPages.WebPartPageUserException: The 'WpNs0' prefix has already been mapped to a namespace.

Source Error:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

Stack Trace:


[WebPartPageUserException: The 'WpNs0' prefix has already been mapped to a namespace.]
Microsoft.SharePoint.ad.a(i A_0) +402
Microsoft.SharePoint.g.c() +13
Microsoft.SharePoint.ad.c(Int32 A_0) +66
Microsoft.SharePoint.ad.d(Int32 A_0) +35
Microsoft.SharePoint.ad.a(Boolean A_0) +190
Microsoft.SharePoint.g.a() +82
Microsoft.SharePoint.SPWeb.a(Uri A_0, bn A_1, HttpContext A_2, Boolean A_3, Boolean A_4, Int64& A_5, SPWebPartCollection& A_6) +190
Microsoft.SharePoint.ApplicationRuntime.SharePointHandler.SPProcessRequest(HttpContext context) +356

[ApplicationException: Exception of type System.ApplicationException was thrown.]
Microsoft.SharePoint.ApplicationRuntime.SharePointHandler.SPProcessRequest(HttpContext context) +1073
Microsoft.SharePoint.ApplicationRuntime.SharePointHandler.SPProcessRequest(HttpContext context) +0
Microsoft.SharePoint.ApplicationRuntime.SharePointHandler.ProcessRequest(HttpContext context) +21
System.Web.CallHandlerExecutionStep.System.Web.HttpApplication+IExecutionStep.Execute() +179
System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +87




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Version Information: Microsoft .NET Framework Version:1.1.4322.2300; ASP.NET Version:1.1.4322.2300