Re: advertising with flash plugin
I didnt mention any of that in my first post because I didnt think it was relevant. I thought the problem was to do with the object html tag which embeds the flash plugin, as other sites with flash do not cause a popup dialog.
I have since investigated mozillas source code and I believe it is a combination of factors. The popup is shown by mozillas 'nullplugin' which handles any other unhandled plugin object types. It has a bit of code which pops up a dialog when clicked. I've looked at the source code for the nullplugin and the popup is only shown in response to a mouse release event (from any button). Something about the nvnews site or html document structure (or some other bug in mozilla) somehow causes the plugin wiget to get a mouse event. I don't know what it is as I tried navigating to the page without using the mouse at all and the popup still showed. Other sites embedding flash etc don't show a popup at all unless I actually click on them.
Anyway, I've just deleted the nullplugin - that suits me fine.
Also, Mozilla have accepted a patch already (from someone else) that makes the nullplugin respond only to button 1.