I presume onmousemove/onmouhappywn/onmouseup events still fire, you could try tracking the mouse with them, but you'd need to manually check for the mouse being over the elements. I've not tried it, so it may not work.
I have been able to use onclick= in the HTML of the g elements without any problems. I can also define gelement.onmouhappywn = in the JavaScript and it works fine as well, so it seems like they pick up the events without any issues. My real problem is getting the <object> tag to pick them up.
In thinking about this more, it appears that I'm suffering the same problem many others have had with how the Sidebar handles transparency. That is, I am getting the exact same behavior as someone who is trying to capture mouse events over the transparent parts of backgrounds. You can left click and drag, you can right click and get the context menu, but you can't capture any mouse events in the code. This makes some sense to me if I think of it as the gbackground element layering over my <object> but making itself transparent wherever the overlap occurs.
I don't think it's going to be productive to try and use g:background to solve any event-driven issues you have; I'd rather figure out why onclick isn't working on the <object> tag. Is this something that works OK if you try it in IE?
No, the ActiveX object doesn't support onclick events, so the only solution would be to layer something over it, which I don't think is really doable. I had pretty much resigned myself to finding some kind of workaround until I stumbled across the g:background situation. It was more of an oddity than a potential solution, and I was just looking for some logic behind it.
Aside from that, does anyone know of any good ways to capture mouse events over ActiveX controls?