Could not hide plugin placeholder

[renyouguo]

Test:
http://www.fodian.net/tools/

rule：
|http://www.fodian.net/pics/002-1.swf|$domain=www.fodian.net

[gorhill]

I need to add embed as a collapsible element.

[gorhill]

This was partly fixed a while ago, I added embed in the list of elements to query and hide. With ee81436, the fix is complete.