ASSERT(m_pCtrlSite == NULL) error on activex addition

I draged and droped an added registered activex control FPCapX on simple dialog in dialog based application used to display image from hardware attached.
When I start using any of its method which interact with hardware ,it gives this assert in debug mode,and in release mode it simply does not work.Control works very simply in VB applications. Actually each of this methods internally calls InvokeHelper function where the assert comes. When I searched on google about bug I found that
Activex Control is not initialised. Can anyone help on this please.


In google search only one relevant article comes Actually in that article one is trying to set values to activex control before its dialog gets initialised. but I am trying to use capture mwthod of activex far after dialog is loaded and when user clicks button capture. One more point i want to tell you, if instead of drag and drop from control toolbar if I create control using create function of it,it doesnot give assertion but it simply does nothing

Some code snippets might be useful.