In Ubuntu Hardy you were used to be asked to grant permission to the website you were visiting to take control on your webcam (through some flash popup with the settings). It seems that recent versions of Adobe flash player (the updated ones for Intrepid and Jaunty since June 2009, at least, and probably before also) have a bug which doesn't ask the user to grant access to a site when visiting it. Like ustream.tv for streaming using your webcam, as example.
The workaround is to grant access to that website by default without attempting to ask you each time.
* You need to go to:
http://www.macromedia.com/support/do...manager06.html
* Choose the "Website privacy settings" * Select the site from the list of visited websites. * click on the option "always allow" above the list.
You should see that the icon on the left of that site in the list changes from yellowish to green colour. That's it.
Try again visiting that website, ustream.tv in this example, and your webcam should be streaming again as it used to do back with Hardy.
Enjoy!