How to install an Addin which is develpoed on older version of VS .Net

[Srini]

Hi all
Any body have an idea about How to install an Word addin which is
developed in VS .Net 2003. i need to install it in my Application which
is develpoed in VS.Net 2005. i am getting a watson saying invalid Cast
Exception
Actually our solution developedin VS 2003 and VS 2005 also.When we
tried to develpoe an word addin in VS 2005, Addin getting installed but
we didnt see any changes
If we develope in VS 2003 we are able to see the changes in Addin.but
we could not use DLLs of our latest solution develped in VS 2005.
because we are writing addin in VS 2003(we are using some of our
application dlls to access some properties here)

Can anybody help me inthis issue

Error message

Unable to cast COM object of type
'Microsoft.BusinessSolutions.SBA.Interop.Word.Appl icationClass' to
interface
type 'Microsoft.BusinessSolutions.SBA.Interop.Word._App lication'. This
operation failed because the QueryInterface call on
the COM component for the interface with IID
'{00020970-0000-0000-C000-000000000046}' failed due to the following
error: No
such interface supported (Exception from HRESULT: 0x80004002
(E_NOINTERFACE)).