This should be fixed in Ubuntu 11.10 "Oneiric Ocelot" with lightspark 0.5.1-0ubuntu1
According to the upstream release notes at http://janimo.blogspot.com/2011/09/lightspark-051-released.html : "For users, the most visible change is that YouTube is working again - their player keeps getting updated and sometimes it introduces Flash APIs or VM opcodes which are not fully implemented in Lightspark, resulting in breakage." A PPA for Ubuntu 11.04 "Natty Narwhal can be found at https://launchpad.net/~sparkers/+archive/daily/ Can you please test and let us know? ** Changed in: lightspark (Ubuntu) Status: Confirmed => Incomplete -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/802213 Title: Lightspark in Firefox notes Youtube video unsupported To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/lightspark/+bug/802213/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs