Invoking a VB service from WebMethods

I am using webMethods 6.1. I have compiled the sample vb dll as given in WmSamples and registered it. When I invoke the helloWorld method from a external visual basic exe by passing a Values object, the dll works fine. But when I invoke the same using webMethods win32:COM:invoke methods, i get no exception, but the method doesnt get called. Whereas if i use win32:COM:invokeLate method, an exception is raised java.lang.reflect.InvocationTargetException: null.

Please help