I'm running a Wubi install of Ubuntu 10.04 on an ASUS, using Firefox 3.6.20,
Mozilla Firefox for Ubuntu canonical. I'm also running noscript, and I've
disabled it, or rather allowed all the scripts on the page.

Recently, I've run into a problem playing flash video, such as youtube.
Whenever I go to youtube or any other site with .flv video, I get this:

"Additional plugins are required to display all of the media on this page.

Install missing plugins..."

Further down on the page, youtube tells me

"You need to upgrade your Adobe Flash Player top watch this video.
Download it from Adobe."

I click on the button in the notification area that says "Install Missing
Plugins" and I get

"Plugin Finder Service

Available Plugin Downloads

Choose a Plugin for media type application/x-shockwave-flash:

Adobe Flash Player (installer)
Swfdec SWF player
Gnash SWF Player

Press Next to install these plugins."

When I press Next, I get a window that says "Package 'flashplugin-installer'
is already installed"

I click close, and another window says "Firefox finished installing the
missing plugins: Adobe Flash Player (installer)--Installed"

I've also tried downloading directly from Adobe, which installed
successfully. I still can't view .flv videos.

I've run update manager, I've updated Firefox, I've fallen back to older
updates, but no joy.

Any ideas?