Invoking Application based on UID.

Hi,

I have been using jawin succesfully in my application, accessing COM through
the Dispatch interface. This easy to do, minding a well documented API (Like iTunes).

Now I try to access COM through the GUID of an application, as retrieved from the registry.
I have the feeling that I am close to the solution, but I think I am overlooking something.

Specifically I query the Registry to retrieve a file extension's 'PersistentHandler'.
Here is the code below. I can create the extend Dispatch class named "ipBrowser" but
invoking a method on it throws a COMexception.

Can someone tell me what I am doing wrong?

        ///// GET A KEY METHOD

        public static String getStringValue(int area, String keyString, String valueString) {
        int key;
        try {
                key = Registry.OpenKey(area,
                    keyString);
            String value = Registry.QueryStringValue(key, valueString);
            Registry.CloseKey(key);
            return value;
                return value;
        } catch (IOException e) {
            e.printStackTrace();
        } catch (COMException e) {
            e.printStackTrace();
        }


        ////////////////////////////////////////
        //  CREATE A
        ///////////////////////////////////////

        String id = ipRegistry.getStringValue(
                RegistryConstants.HKEY_LOCAL_MACHINE,
                "SOFTWARE\\Classes\\.htt\\PersistentHandler", "");
        try {
            Ole32.CoInitialize();
            ipBrowser browser = new ipBrowser(id);
                browser.invoke("Open","www.yahoo.com"); <<<-----------COM EXCEPTION.
            Ole32.CoUninitialize();

        } catch (COMException e) {
            e.printStackTrace();
        }

        ///////////////////////////////////////////
        // EXTEND DISPATH TO register the GUID
        //////////////////////////////////////////
        public class ipBrowser extends DispatchPtr {

        public GUID DIID;

        public int iidToken;

        public ipBrowser(String guid) {
            DIID = new GUID(guid);
            iidToken = IdentityManager.registerProxy(DIID,
                    ipLaunchBrowser.class);
        }

        /**
         * @see org.jawin.IUnknown#getIIDToken()
         */
        public int getIIDToken() {
            return iidToken;
        }

    }

Thank / Christophe