Have seen similar posts on the FlickR site itself , example: I'm posting this, because the current title of another forum thread: "[acknowledge issue-fixed]Share this button" gives me the feeling that the Flickr staff may incorrectly assume that issues regarding the "Share this" and the "Action" functions in Flickr have been resolved and as a result of this assumption may no longer be reading new comments in the aforementioned forum thread that can be found at:

www.flickr.com/help/forum/en-us/72157625137034951/

Since yesterday, I have been experiencing problems with Flickr. When I click onto Actions or Share in my Photostream, the blue and pink Flickr balls appear and then get stuck in rotation mode. I experienced these problems in Firefox 3.6.11 and in Firefox 3.6.12. Clearing the cache, restarting Flickr and disabling add-ons hasn't solved anything.

In several threads (including the one that can be accessed by clicking the above link) other Flickr users (mostly, but NOT exclusively, Firefox users) have made it clear that they too are still experiencing problems with the Actions and Share this functions, so it appears that the issue isn't fixed (for everyone) yet. Posted at 7:56AM, 30 October 2010 PDT

Did you try the suggestions in the other thread?

http://www.flickr.com/help/forum/en-us/72157625148033605/

Yes, finally fixed it by going to congfig: about.dom ,etc. and setting the one line to true per the thread. Was this a Mozilla issue?

If you didn't disable that setting yourself then an extension or some security software may have changed it.