Excel Addin

Iam trying to create a Excel Addin using Visual C# Extensibility projects and after building the project , the Dll is registered and the registry
entries are added on to the registry key
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office\Excel\Addins

but when i open excel it is not loading the addin.
In the onConnection function i have added code to display the message box, but the control never goes there ...that means the DLL is not loaded .


When i try adding the dll manually using the Excel/Tools/Addins the message
"The file you selected does not contain a new Automation server or you do not have sufficient priveleges to register
the Automation server" comes up

Iam using Excel 2003