I can't click on the flash plugin 'Allow/Deny'

Ubuntu, Chrome & Firefox both had this.  IM app tried to invoke a flash URL to launch a video share service.  The Flash 'allow/deny access to your camera' dialogue box would pop up but nothing was active, no clicky mouse.

Go to :

http://www.macromedia.com/support/documentation/en/flashplayer/help/settings_manager09.html

and it displays the flash global settings for your workstation.  Set the site you want to allow to 'don't prompt' and all is well.