Problem playing web video

Hi!

Using RC3 presently.

When I try to watch an online video, like Twit or any other site via their respective addon I either get an audio only and then a crash to the desktop or I get a delay of about 30 seconds before the video start playing... Any idea?

I get no such delay when the video are played via my web browser.

Are the addons in the official repo certified compatible with RC3?