I've been trying to get a decent speed on Youtube Flash videos since Ubuntu 11.10 but I still get the same slow down. It seens to be a 64bit only problem. I've already tried to use FlashAid on Firefox but the slowness wasnt solved. My currently best result is using Google Chrome (not Chromium) and his proprietary flash plugin. Full screen works fine on 480p but anything greater than that get slow and a ghost effect in the video appears.
This shouldnt be hardware problem (i5 2430, and the HD3000 should be fine for that), on Windows everthing works fine.
Even the "OverrideGPUValidation" for the Adobe plugin didnt work.
Chrome Flash Version Descrição: Shockwave Flash 11.4 r31 Versão: 18.104.22.168 Local: /opt/google/chrome/PepperFlash/libpepflashplayer.so
Firefox Flash Version Nome: Shockwave Flash Versão: 11.2 r202 Local: /usr/lib/mozilla/plugins/libflashplayer.so
Thanks in advance,