StoreAPI.exe Error

When I try to add my custom schema assembly to the default store, I get the following error:

>storeapi -addSchema DefaultStore MadProps.Comicster.Storage.dll Microsoft (R) WinFS Store Utility Copyright (C) Microsoft Corporation. All rights reserved. Schema MadProps.Comicster.Storage.dll cannot be installed into DefaultStore. The reason for the failure is unknown. Server error code is 23999.

What could be the problem? Should my assembly's filename not have dots in it? I have used "wfssign.exe -CheckPublicKeyToken" to make sure the DLL is properly signed etc.

Thanks,
Matt

[809 byte] By [mabster] at [2008-2-4]